As filed with the Securities and Exchange Commission on March 13,October 4, 2019

RegistrationNo. 333-229913333-            

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

PRE-EFFECTIVE AMENDMENT NO. 1

TO

FORMS-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

GLACIER BANCORP, INC.

(Exact name of registrant as specified in its charter)

49 Commons Loop, Kalispell, Montana 59901 (406)756-4200

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

RANDALL M. CHESLER

President and Chief Executive Officer

49 Commons Loop

Kalispell, Montana 59901

(406)756-4200

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies of communications to:

Approximate date of commencement of proposed sale of securities to the public:

As soon as practicable after this Registration Statement becomes effective and upon completion of the merger described in the enclosed document.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box.  ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, a smaller reporting company, or an emerging growth company. See definitionthe definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule12b-2 of the Exchange Act. (Check one):

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided purchase to Section 7(a)(2)(B) of the Securities Act. ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT WILL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION STATEMENT WILL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF THE SECURITIES ACT OF 1933, OR UNTIL THIS REGISTRATION STATEMENT WILL BECOME EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION, ACTING PURSUANT TO SECTION 8(A), MAY DETERMINE.

Information contained herein is subject to completion or amendment. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. These securities may not be sold prior to the time the registration statement becomes effective. This document shall not constitute an offer to sell nor shall there be any sale of these securities in any jurisdiction in which such offer or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction.

PRELIMINARY—SUBJECT TO COMPLETION—DATED MARCH 13,OCTOBER 4, 2019

MERGER PROPOSED – YOUR VOTE IS VERY IMPORTANT

Dear FNB BancorpState Bank Corp. Shareholders:

As you may know, the boards of directors of FNB BancorpState Bank Corp. (“FNB”SBC”) and Glacier Bancorp, Inc., Kalispell, Montana (“Glacier”) have each unanimously approved a merger of FNBSBC with and into Glacier, subject to approval by FNBSBC shareholders and appropriate bank regulators. Immediately following the merger, FNB’sSBC’s subsidiary The First NationalState Bank of LaytonArizona (the “Bank”) will be merged into Glacier’s subsidiary Glacier Bank (“Glacier Bank”), subject to approval of appropriate bank regulators.

Under the terms of the Plan and Agreement of Merger, dated January 16,September 30, 2019 (the “merger agreement”), each outstanding share of FNBSBC common stock (including each share of unvested restricted stock) will be exchanged for 0.6474a “unit” comprised of $1.69 and 0.3706 shares of Glacier common stock, subject to certain adjustments. The common stock of Glacier trades on The NASDAQ Global Select Market under the symbol “GBCI.” SBC’s common stock is currently quoted on the OTC Pink under the symbol “SBAZ.”

The amountstock portion of Glacier common stock exchanged for each share of FNB common stockunit is subject to adjustment in the event that the average closing price for Glacier common stock over a20-day period prior to closing is more than $46.63$47.31, or less than $32.44, or less than $34.47,$34.97, if such stock price has also declined by ten percentage points more thanunderperformed the KBW Regional Bank Index.Index by more than fifteen percentage points, or less than $32.91. In thatsuch event either Glacier or FNB,SBC, respectively, may provide notice to terminate the merger agreement, provided thatbut the merger agreement will not be terminated if either FNBSBC or Glacier, as the case may be, elects to adjust the number of sharesconsideration to be issued in the merger, as described in this proxy statement/prospectus. Glacier may also elect to pay additional cash consideration in lieu of increasing the number of shares to be issued in the merger.

The merger agreement establishes a minimum requirement for FNB’scash portion of each unit is subject to adjustment depending on SBC’s capital ($39,285,000) prior to the closing of the merger.merger, calculated in accordance with the merger agreement. If FNB’sSBC’s capital is less than the minimum required, which is $63,611,000 (subject to specified adjustments), the cash portion of each unit will be reduced on a pro rata basis by the amount of such deficiency. If SBC’s closing capital, after being adjusted in accordance with the terms of the merger agreement, to take into account any transaction expenses in excess of amounts permitted under the merger agreement, is in excess of the minimum required, FNBSBC may pay a special dividend to its shareholders in the amount of such excess. If FNB’s closing capital is less than the minimum required, the total Glacier stock consideration will be reduced by a number of shares equal in value to the difference between the required amount of FNB closing capital and the amount of the actual FNB closing capital, as adjusted.

Assuming for purposes of illustration only that (i)there is no increase or reduction of the cash portion of each unit, and(ii) the average closing price for Glacier common stock is $41.06,$[], which was the closing price of Glacier common stock on March 11,[], 2019, as quoted on theThe NASDAQ Global Select Market, and that there is no reduction in the exchange ratio due to the FNB closing capital being less than the required amount, for each of your shares of FNBSBC common stock, you will receive 0.6474 Glacier sharesconsideration with an estimated current value of $26.58.$[], consisting of a combination of $1.69 in cash and 0.3706 shares of Glacier common stock (valued at $[]).

Assuming the exchange of all outstanding FNBSBC common stock for Glacier common stock and cash in accordance with the merger agreement FNBand the stock portion of each unit is not adjusted as described above, SBC shareholders will, in the aggregate, ownreceive approximately 2.36%3,007,353 shares of Glacier common stock in the merger, representing approximately 3.4% of Glacier’s outstanding common stock followingafter taking into account Glacier shares to be issued in the merger.

FNB BANCORPSTATE BANK CORP.

12 South MainLake Havasu City, Arizona 86403

Layton Utah 84041

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

TO BE HELD APRIL 18,ON [], 2019

TO THE SHAREHOLDERS OF FNB BANCORPSTATE BANK CORP.:

A special meeting of shareholders of FNB BancorpState Bank Corp. (“FNB”SBC”) will be held on April 18,[], 2019, at 10:00 a.m.[] [].m. Mountain Standard Time, at the Davis Conference Center located at 1651 North 700 West, Layton, Utah 84041.[], Lake Havasu City, Arizona. The special meeting is for the following purposes:

Holders of record of FNBSBC common stock at the close of business on March 6,[], 2019, the record date for the special meeting, are entitled to notice of, and to vote at, the special meeting or any adjournments or postponements of it. The affirmative vote of the holders of at least a majority of the outstanding shares of FNB’s outstandingSBC’s common stock entitled to vote is required for approval of the merger agreement. To that end, FNB’sSBC’s directors and executive officers and certain significant shareholders have signed agreements to vote their shares in favor of the merger agreement. SuchAs of the record date, such persons arewere entitled to vote 1,357,605[] shares representing approximately 42.95%[]% of all outstanding shares of FNBSBC common stock, excluding shares of unvested restricted stock. As of March 6, 2019,the record date, there were 3,160,969[] shares of FNBSBC common stock outstanding.outstanding, excluding [                    ] shares of unvested restricted stock, which do not have voting rights.

FNBSBC shareholders have the right to dissent from the merger and obtain payment of the fair valueof their shares of FNBSBC common stock under the Utah Revised Business Corporations Act (“URBCA”), Sections 1301 through 1331.applicable provisions of Arizona law. A copy of the provisions regarding dissenters’ rights is attached asAppendix B to the accompanying proxy statement/prospectus. For details of your dissenters’ rights and how to exercise them, please see the discussion under “The Merger – Dissenters’ Rights.”

Your vote is important. Whether or not you plan to attend the special meeting, please complete, sign, datewe encourage you to submit a proxy to vote your shares as promptly as possible in order to make certain that you are represented at the meeting. You may submit a proxy over the Internet, as well as by telephone or by completing, signing, dating and promptly returnreturning the accompanying proxy using the enclosed envelope. If for any reason you should desire to revoke your proxy, you may do so at any time before it is voted at the meeting.If you do not vote your shares, it will have the same effect as voting against the merger.

The board of directors of FNBSBC has determined that the merger agreement is fair to, advisable, and in the best interests of FNBSBC and its shareholders and unanimously recommends that you vote FOR approval of the merger agreement. With regard to its recommendation that shareholders vote FOR approval of the merger agreement, the board of directors of FNBSBC considered a number of factors, as discussed in “ Background“Background of and Reasons for the Merger” beginning on page 18.23. Such factors also constituted the reasons that the board of directors determined to approve the merger agreement and to recommend that FNBSBC shareholders vote in favor of the merger agreement.

You will receive instructions on how to exchange your shares of FNBSBC common stock for the merger consideration promptly after the closing of the merger.

Layton, UtahLake Havasu City, Arizona

March 13,[], 2019

REFERENCES TO ADDITIONAL INFORMATION

Glacier

This proxy statement/prospectus incorporates important business and financial information about Glacier from documents that Glacier has previously filed with the Securities and Exchange Commission (“SEC”) and that are contained in or incorporated by reference into this proxy statement/prospectus. For a listing of Glacier documents incorporated by reference into this proxy statement/prospectus, please see the section entitled “Where You Can Find More Information.” This information is available for you to review at the SEC’s website athttp://www.sec.gov.

You may request copies of this proxy statement/prospectus and any of the documents incorporated by reference into this proxy statement/prospectus or other information concerning Glacier, without charge, by telephone or written request directed to:

Glacier Bancorp, Inc.

49 Commons Loop

Kalispell, Montana 59901

ATTN: Ron Copher, Corporate Secretary

Telephone: (406)751-7706

Certain reports can also be found on Glacier’s website atwww.glacierbancorp.com.

Glacier’s common stock is traded on theThe NASDAQ Global Select Market under the symbol “GBCI.”

You will not be charged for the documents that you request.If you would like to request documents, please do so by April 11,[], 2019 in order to receive them before the FNBSBC special shareholders’ meeting.

FNBState Bank Corp.

FNBSBC does not have a class of securities registered under Section 12 of the Securities Exchange Act of 1934 (the “Exchange Act”), is not subject to the reporting requirements of Section 13(a) or 15(d) of the Exchange Act, and accordingly does not file documents or reports with the SEC.

If you have questions concerning the merger or this proxy statement/prospectus, would like additional copies of this proxy statement/prospectus, would like copies of FNB’sSBC’s articles of incorporation or bylaws, or would like copies of FNB’sSBC’s historical consolidated financial statements or need help voting your shares, please contact:

FNB BancorpState Bank Corp.

12 South Main1771 McCulloch Boulevard

Layton, Utah 84041Lake Havasu City, Arizona 86403

ATTN: Nic BementKaren Gibbs, Corporate Secretary

(801)(928)813-1600302-5165

TABLE OF CONTENTS

i

QUESTIONS AND ANSWERS

Why am I receiving these materials?

We are sending you these materials to solicit your proxy to vote in favor of the merger and to help you decide how to vote your shares of FNB BancorpState Bank Corp. (“FNB”SBC”) common stock with respect to its proposed merger with Glacier Bancorp, Inc. (“Glacier”). The merger cannot be completed unless FNBSBC receives the affirmative vote of the holders of at least a majority of the outstanding shares of FNB’sSBC’s common stock. FNBstock entitled to vote on the matter. SBC is holding a special meeting of shareholders to vote on proposals relating to the merger. Information about the special meeting is contained in this document. See “FNB“SBC Special Shareholders Meeting.”

This document is both a proxy statement of FNBSBC and a prospectus of Glacier. It is a proxy statement because the officers and board of directors of FNBSBC (the “FNB“SBC Board”) are soliciting proxies from FNBSBC’s shareholders in connection with voting on the merger. It is a prospectus because Glacier will issue shares of its common stock in exchange for shares of FNBSBC common stock as a portion of the consideration to be paid in the merger.

What will FNBhappen in the merger?

In the proposed merger, SBC will merge with and into Glacier, with Glacier surviving the merger. Immediately following the merger, State Bank of Arizona (the “Bank”) will be merged into Glacier’s subsidiary Glacier Bank. Shares of Glacier will continue to trade on The NASDAQ Global Select Market, with the trading symbol “GBCI.”

What will SBC shareholders receive in the merger?

Under the terms of the merger agreement, each share of FNBSBC common stock (including each share of unvested restricted stock) will be exchanged for 0.6474a “unit” comprised of 0.3706 shares of Glacier common stock and $1.69 in cash, subject to adjustment as described below.

Assuming for purposes of illustration only that the average closing price for Glacier common stock is $41.06$[] (which was the closing price for Glacier common stock on March 11,[], 2019), and that there is no reduction in the exchange ratio due to the FNB Closing Capital (discussed below) being less than the required amount, each share of FNBSBC common stock would be exchanged for 0.3706 shares of Glacier common stock with a total value equal to $26.58.$[], in addition to the cash consideration of $1.69 per share.

IfThe stock portion of each unit may be adjusted in certain circumstances based on whether Glacier common stock is trading either higher or lower than prices specified in the FNBmerger agreement immediately prior to the closing of the merger, in order to avoid termination of the merger agreement.

The cash portion of each unit will be subject to reduction if the “SBC Closing Capital, (as” as defined in the merger agreement)agreement, is less than the target of $63,611,000, subject to certain adjustments. In such event, the cash portion of each unit will be reduced on a pro rata basis by the amount of such deficiency.

If the SBC Closing Capital exceeds $39,285,000,$63,611,000, subject to certain adjustments, FNBSBC may, upon written notice to Glacier and effective immediately prior to the closing of the merger, declare and pay a special dividend to its shareholders in the amount of such excess.

If the FNB Closing Capital is less than $39,285,000, the total number of Glacier shares issued in the merger will be reduced by a number of shares equal in value to the differential between $39,285,000 and the actual FNB Closing Capital.

The amount of Glacier common stock exchanged for each share of FNB common stock may also be adjusted in certain circumstances if Glacier common stock is trading either higher or lower than prices specified in the merger agreement immediately prior to the closing of the merger, in order to avoid termination of the merger agreement as follows:

Assuming the exchange of all outstanding FNBSBC common stock for Glacier common stock as a portion of the merger consideration in accordance with the merger agreement FNBand the stock portion of each unit is not adjusted as described above, SBC shareholders will own,receive, in the aggregate, approximately 2.36%3,007,353 shares of Glacier common stock in the merger, representing approximately 3.4% of Glacier’s outstanding common stock followingafter taking into account Glacier shares to be issued in the merger.

Will I receive any fractional shares of Glacier common stock as part of the merger consideration?

No. Glacier will not issue any fractional shares of Glacier common stock in the merger. Instead, Glacier will pay you the cash value of a fractional share (without interest) in an amount determined by multiplying the fractional share interest to which you would otherwise be entitled by the average of the closing sales prices of one share of Glacier common stock on The NASDAQ Global Select Market for the 20 trading days ending on the tenth business day immediately preceding the effective date of the merger.

How soon after the merger is completed can I expect to receive my merger consideration?

Glacier will work with its exchange agent, American Stock Transfer & Trust Company, LLC, to distributecomplete the exchange of your SBC stock certificates for consideration payable in the merger as promptly as practicable following the completion of the merger.

Will I be able to trade the shares of Glacier common stock that I receive in the merger bemerger?

You may freely transferable?

Yes. Thetrade the shares of Glacier common stock issued in the merger, will be transferable freeunless you are an “affiliate” of restrictionsGlacier as defined by Rule 144 under federalthe Securities Act of 1933, as amended. Affiliates consist of individuals or entities that control, are controlled by or are under the common control with Glacier, and state securities laws.include the executive officers and directors of Glacier after the merger and may include significant shareholders of Glacier.

When will the merger occur?

We presently expect to complete the merger duringas early as the secondfourth quarter of 2019. The actual timing of the transaction is subject to a number of factors (primarily regulatory approvals), many of which are beyond the control of Glacier and FNB.SBC. The merger is conditioned upon and will occur after the approval of the merger agreement by the affirmative vote of holders of at least a majority of the outstanding shares of FNBSBC common stock entitled to vote on the matter at the SBC special meeting, after the merger has received regulatory approvals, and following the satisfaction or waiver of the other conditions to the merger described in the merger agreement and summarized under “The Merger” below.

The merger agreement provides that in the event the closing has not occurred by November 30, 2019, the first date on which the closing may occur is February 29, 2020.

If the merger does not occur by SeptemberApril 30, 2019,2020, either Glacier or FNBSBC may unilaterally terminate the merger agreement. However, if asagreement, subject to an extension of September 30, 2019, the condition to closing that all required governmental regulatory approvals have been obtained has not been satisfied, then the deadline for closing of the merger will be extended to on or before November 30, 2019, if Glacier notifies FNB in writing on or prior to September 30, 2019 of its election to extend such closing deadline.date under certain circumstances.

When and where will the special meeting take place?

FNBSBC will hold a special meeting of its shareholders on April 18,[], 2019, at 10:00 a.m.[] [].m. Mountain Standard Time, at the Davis Conference Center located at 1651 North 700 West, Layton, Utah 84041.[], Lake Havasu City, Arizona.

Who may vote at the special meeting?

The FNBSBC Board has set March 6,[], 2019 as the record date for the special meeting. If you were the owner of FNBSBC common stock at the close of business on March 6,[], 2019, you may vote at the special meeting. Each holder of SBC common stock is entitled to one vote for each share of SBC common stock owned as of the record date.

What constitutes a quorum for the special meeting?

The quorum requirement for the special meeting is the presence in person or by proxy of a majority of the total number of outstanding shares of SBC common stock entitled to vote.

What vote is required to approve the merger agreement?

Approval of the merger agreement requires the affirmative vote of the holders of at least a majority of the outstanding shares of FNB’s outstandingSBC’s common stock.stock entitled to vote on the matter. As described in this proxy statement, FNB’sstatement/prospectus, SBC’s directors and executive officers and certain significant shareholders have agreed to vote the shares they are entitled to vote in favor of the merger agreement. As of the record date, hereof, such persons arewere entitled to vote 1,357,605[] shares of FNBSBC common stock, representing approximately 42.95%[]% of all outstanding shares of FNBSBC common stock, excluding shares of unvested restricted stock. See “FNB“SBC Special Shareholders’ Meeting” and “The Merger – Voting Agreement.Agreements.”

What vote is required to approve the adjournment of the special meeting, if necessary or appropriate?

If less than a quorum is represented at the special meeting, a majority of the shares so represented may adjourn the special meeting without further notice. The proposal to adjourn the special meeting, if necessary or appropriate, including adjournments to solicit additional proxies, will be approved if the votes cast in favorapproved by a majority of the proposal exceedvoting power present at the votes cast against the proposal,special meeting, whether in person or by proxy, assuming a quorum is present. If less than a quorum is represented atEach of the Voting Agreements entered into by SBC’s directors and executive officers and certain significant shareholders provides that such persons have agreed to vote the shares subject to such agreement in favor of any proposal to adjourn the special meeting a majority ofif there are not sufficient votes to approve the shares so represented may adjourn the meeting without further notice.merger agreement.    

How do I vote?

If you were a shareholder of record on March 6,[], 2019, you may vote on the proposals presented at the special meeting in person or by proxy. We urge you to vote promptly by submitting a proxy to vote through the Internet, by telephone, or by completing the enclosed proxy card. Even if you plan to attend the special meeting, we recommend that you vote your shares in advance as described below so that your vote will be counted if you later decide not to attend the special meeting.

You may cast your vote by submitting a proxy through the Internet or by telephone by following the instructions included on the enclosed proxy card or by mail by completing, signing and dating the enclosed proxy card and returning it to us promptly in the enclosed envelope. ReturningSubmitting a proxy through the Internet or by telephone or returning the proxy card will not affect your right to attend the special meeting and vote.

If you choose to vote your shares in person at the special meeting, please bring the enclosed proxy card and proof of identification.

If your shares are registered in “street name” in the name of a broker or other nominee and you wish to vote at the special meeting, you will need to obtain a legal proxy from your bank or brokerage firm. Please consult the voting form sent to you by your bank or broker to determine how to obtain a legal proxy in order to vote in person at the meeting.

What if I fail to submit a proxy or to instruct my broker, bank or other nominee?

If you fail to properly submit a proxy or to instruct your broker, bank or other nominee to vote your shares of SBC common stock, and you do not attend the special meeting and vote your shares in person, your shares will not be voted. This will have the same effect as a vote “AGAINST” approval of the merger agreement, but will have no impact on the outcome of the other proposal.

Can I attend the special meeting and vote my shares in person?

Yes. Although the SBC Board requests that you submit a proxy through the Internet, by telephone or by returning the proxy card accompanying this proxy statement/prospectus, all shareholders are invited to attend the shareholder meeting. Shareholders of record on [], 2019 can vote in person at the special meeting. If your shares are held by a broker, bank or other nominee, then you are not the shareholder of record and you must bring to the shareholder meeting appropriate documentation from your broker, bank or other nominee to enable you to vote at the shareholder meeting.

Can I change my vote after I have mailedsubmitted my signed proxy card?proxy?

Yes. YouIf you do not hold your shares in “street name,” there are three ways you may change your vote at any time after you have submitted your proxy and before your proxy is voted at the special meeting. If your shares of FNB common stock are held in your own name, you may change your vote as follows:meeting:

If my shares are held in “street name” by my broker, bank or other nominee, will my broker, bank or other nominee automatically vote my shares for me?

No. Your broker, bank or other nominee will not vote your shares unless you provide instructions to your broker, bank or other nominee on how to vote. You should instruct your broker, bank or other nominee to vote your shares by following the instructions provided by the broker, bank or nominee with this proxy statement/prospectus.

How does the FNBSBC Board recommend that I vote?

The FNBSBC Board unanimously recommends that FNBSBC shareholders vote “FOR” the proposals described in this proxy statement/prospectus, including in favor of approval of the merger agreement.

What do I need to do now?

We encourage you to read this proxy statement/prospectus and related information in its entirety. Important information is presented in greater detail elsewhere in this document, and documents governing the merger are attached as appendices to this proxy statement/prospectus. In addition, much of the business and financial information about Glacier that may be important to you is incorporated by reference into this document from documents separately filed by Glacier with the Securities and Exchange Commission (“SEC”). This means that important disclosure obligations to you are satisfied by referring you to one or more documents separately filed with the SEC.

Following review of this proxy statement/prospectus,please complete, sign,submit a proxy through the Internet, by telephone or by completing, signing, and datedating the enclosed proxy card and return it in the enclosed envelopeas soon as possible so that your shares of FNBSBC common stock can be voted at FNB’sSBC’s special meeting of shareholders.

What happens if I sell my shares after the record date but before the special meeting?

The record date of the special meeting is earlier than the date of the special meeting and the date that the merger is expected to be completed. If you sell or otherwise transfer your shares after the record date, but before the date of the special meeting, you will retain your right to vote at the special meeting, but you will not have the right to receive the merger consideration to be received by shareholders in the merger. In order to receive the merger consideration, a shareholder must hold his or her shares through completion of the merger.

What do I do if I receive more than one proxy statement/prospectus or set of voting instructions?

If you hold shares directly as a record holder and also in “street name” or otherwise through a nominee, you may receive more than one proxy statement/prospectus and/or set of voting instructions relating to the special meeting. These should each be voted and/or returned separately in order to ensure that all of your shares are voted.

Should I send in my common stock certificates now?

No.Please do not send your FNBSBC common stock certificates with your proxy card. You will receive written instructions from Glacier’s exchange agent promptly following the closing of the merger on how to exchange your FNBSBC common stock certificates for the merger consideration.

What risks should I consider?consider in deciding whether to vote for approval of the merger agreement?

You should review carefully our discussion under “Risk Factors.” You should also review the factors considered by the FNBSBC Board in approving the merger agreement. See “Background of and Reasons for the Merger.”

What are the material United States federal income tax consequences of the merger to FNBSBC shareholders?

Glacier and FNBSBC expect to report the merger of FNBSBC with and into Glacier as atax-free reorganization for U.S. federal income tax purposes under Section 368(a) of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). It is a condition to the closing of the merger that Miller Nash Graham & Dunn LLP, tax counsel to Glacier, delivereach party receives an opinion addressed to Glacier and FNBfrom its respective legal counsel that the merger will qualify as a reorganization under Section 368(a).

RISK FACTORS

In addition to the other information contained in or incorporated by reference into this document, including the matters addressed under the caption “Cautionary Note Regarding Forward-Looking Statements,” you should consider the matters described below carefully in determining whether or not to approve the merger agreement and the transactions contemplated by the merger agreement.

Risks Associated with the Proposed Merger

Because you are receiving a fixed number of shares (subject to adjustment) and the market price of the Glacier common stock may fluctuate, you cannot be sure of the value of the shares of Glacier common stock that you will receive.

At the time of the FNBSBC special shareholder meeting, and prior to the closing of the merger, you will not be able to determine the value of the Glacier common stock that you will receive upon completion of the merger. Any change in the market price of Glacier common stock prior to completion of the merger will affect the value of the consideration that FNBSBC shareholders will receive in the merger. Common stock price changes may result from a variety of factors, including but not limited to general market and economic conditions, changes in Glacier’s business, operations and prospects, and regulatory considerations. Many of these factors are beyond the control of Glacier or FNB. On March 11, 2019, the closing price of Glacier common stock was $41.06.SBC. You should obtain current market prices for Glacier common stock.

The merger agreement provides that the number of shares of Glacier common stock to be issued for each share of FNBSBC common stock in the merger may be decreased or increased, as the case may be, if the average closing price of Glacier common stock, determined pursuant to the merger agreement, is greater than or less than specified prices. If Glacier’s average closing price determined in accordance with the merger agreement is greater than $46.63$47.31 and Glacier elects to terminate the merger agreement, the FNBSBC Board wouldcould determine, without resoliciting the vote of FNBSBC shareholders, whether or not to accept a decrease on aper-share basis in the number of shares of Glacier common stock to be issued in the merger to avoid such termination. See “The Merger – Termination of the Merger Agreement.”

The merger agreement limits FNB’sSBC’s ability to pursue other transactions and provides for the payment of abreak-up fee if FNBSBC does so.

While the merger agreement is in effect, subject to very narrow exceptions, FNBSBC and its directors, officers, employees, agents and representatives are prohibited from initiating or encouraging inquiries with respect to alternative acquisition proposals. The prohibition limits FNB’sSBC’s ability to seek offers from other potential acquirers that may be superior from a financial point of view to the proposed transaction. If FNBSBC receives an unsolicited proposal from a third party that is superior from a financial point of view to that made by Glacier and the merger agreement is terminated, FNBSBC will be required to pay a $3,200,000$6,000,000break-up fee. This fee makes it less likely that a third party will make an alternative acquisition proposal. See “The Merger –Break-Up Fee.”

Combining our two companies may be more challenging, costly or time-consuming than we expect.

Glacier and FNBSBC have operated and, until the completion of the merger, will continue to operate, independently. Although Glacier has successfully completed numerous mergers in the recent past, it is possible that the integration of the Bank into Glacier Bank could result in the loss of key employees, the disruption of the ongoing business of the Bank or inconsistencies in standards, controls, procedures and policies that adversely affect our ability to maintain relationships with customers and employees or to achieve the anticipated benefits of the merger. As with any merger of banking institutions, there also may be disruptions that cause us to lose customers or cause customers to take their deposits out of the Bank.

Unanticipated costs relating to the merger could reduce Glacier’s future earnings per share.

Glacier believes that it has reasonably and conservatively estimated the likely costs of integrating the operations of the Bank into Glacier Bank, and the incremental costs of operating as a combined financial institution. However, it is possible that unexpected transaction costs or future operating expenses, as well as other types of unanticipated adverse developments, could have a material adverse effect on the results of operations and financial condition of Glacier after the merger. If the merger is completed and unexpected costs are incurred, the merger could have a dilutive effect on Glacier’s earnings per share, meaning earnings per share could be less than they would be if the merger had not been completed.

The merger agreement may be terminated in accordance with its terms and the merger may not be completed, which could have a negative impact on SBC.

The merger agreement with Glacier is subject to a number of conditions that must be fulfilled in order to close. Those conditions include: approval by the shareholders of SBC, regulatory approval, the continued accuracy of certain representations and warranties by both parties (subject to the materiality standards set forth in the merger agreement), and the performance by both parties of certain covenants and agreements. In addition, certain circumstances exist in which SBC may terminate the merger, including by accepting a superior proposal or by electing to terminate if Glacier’s stock price declines below a specified level. There can be no assurance that the conditions to closing the merger will be fulfilled or that the merger will be completed.

If the merger agreement is terminated, there may be various consequences to SBC, including:

If the merger agreement is terminated and the SBC Board approves another merger or business combination, under certain circumstances SBC may be required to pay Glacier a $6,000,000 termination fee. SBC’s shareholders cannot be certain that SBC will be able to find a party willing to pay an equivalent or more attractive price than the price Glacier has provisionsagreed to pay in its articlesthe merger.

The fairness opinion delivered to the SBC Board before the execution of incorporation that could impede a takeoverthe merger agreement does not reflect changes in circumstances subsequent to the date of Glacier.the fairness opinion.

Glacier’s articles contain provisions providing for, among other things, preferred stockThe fairness opinion of Davidson was delivered to the SBC Board on September 30, 2019 and super majority shareholder approvalspeaks only as of certain business combinations. Although these provisions were not adopted for the express purpose of preventing or impeding the takeover of Glacier without the approval of Glacier’s board of directors, they may have that effect. Such provisions may prevent you from taking partsuch date. Changes in a transaction in which you could realize a premium over the current market price of Glacier common stock. See “Comparison of Certain Rights of Holdersoperations and prospects of Glacier and FNB Common Stock” for a descriptionSBC, general market and economic conditions, and other factors both within and outside of Glacier’s potential takeover provisions.and SBC’s control may significantly alter the relative value of the companies by the time the merger is completed. Davidson’s opinion does not speak as of the time the merger will be completed or as of any date other than the date of such opinion.

After the merger is completed, FNBSBC shareholders will become Glacier shareholders and will have different rights that may be less advantageous than their current rights.

Upon completion of the merger, FNBSBC shareholders will become Glacier shareholders. Differences in FNB’sSBC’s articles and FNB’sSBC’s bylaws and Glacier’s articles and Glacier’s bylaws will result in changes to the rights of FNBSBC shareholders who become Glacier shareholders. See “Comparison of Certain Rights of Holders of Glacier and FNBSBC Common Stock.”

SBC’s shareholders will have a reduced ownership and voting interest after the merger and will exercise less influence over management.

SBC’s shareholders currently have the right to vote in the election of the SBC Board and on other significant matters affecting SBC, such as the proposed merger with Glacier. When the merger occurs, each SBC shareholder will become a shareholder of Glacier with a percentage ownership of the combined organization that is much smaller than the shareholder’s percentage ownership of SBC. Based on the anticipated number of Glacier common shares to be issued in the merger, it is anticipated that the SBC shareholders will only own approximately 3.4% of all of the outstanding shares of Glacier’s common stock following the merger. Because of this, SBC’s shareholders will have less influence on the management and policies of Glacier than they now have on the management and policies of SBC. Furthermore, shareholders of Glacier do not have preemptive or similar rights, and therefore, Glacier can sell additional voting securities in the future without offering them to the former SBC shareholders, which would further reduce their ownership percentage in, and voting control over, Glacier.

The merger may fail to qualify as a reorganization for federal tax purposes, resulting in the recognition by SBC’s shareholders of taxable gain or loss in respect of their SBC shares.

Glacier and SBC intend the merger to qualify as a reorganization within the meaning of Section 368(a) of the Internal Revenue Code. Glacier and SBC, as a condition to closing, will each obtain an opinion from their respective legal counsel that the merger will qualify as a reorganization for federal tax purposes. These opinions do not bind the Internal Revenue Service or prevent the Internal Revenue Service from adopting a contrary position. Neither Glacier nor SBC has requested and neither intends to request any ruling from the Internal Revenue Service as to the U.S. federal income tax consequences of the merger. If the merger fails to qualify as a reorganization, an SBC shareholder generally would recognize gain or loss in an amount equal to the difference between (i) the sum of the amount of cash and the aggregate fair market value of the Glacier common stock received in the exchange, and (ii) the SBC shareholder’s aggregate adjusted tax basis in the SBC common stock surrendered in the exchange. Furthermore, if the merger fails to qualify as a reorganization, Glacier, as successor to SBC, may incur a significant tax liability since the merger would be treated as a taxable sale of SBC’s assets for U.S. federal income tax purposes.

Failure to complete the merger could negatively impact the stock prices and future businesses and financial results of Glacier and SBC.

If the merger is not completed, the ongoing businesses of Glacier and SBC may be adversely affected, and Glacier and SBC will be subject to several risks, including the following:

In addition, if the merger is not completed, Glacier and/or SBC may experience negative reactions from the financial markets and from their respective customers and employees. Glacier and/or SBC also could be subject to litigation related to any failure to complete the merger or to enforcement proceedings commenced against Glacier or SBC to perform their respective obligations under the merger agreement. If the merger is not completed, Glacier and SBC cannot assure their respective shareholders that the risks described above will not materialize and will not materially affect the business, financial results and stock prices of Glacier and/or SBC.

The merger is subject to the receipt of approvals and/or waivers ornon-objections from governmental authorities that may delay the date of completion of the merger or impose conditions that could have an adverse effect on Glacier.

Before the merger may be completed, various approvals, waivers ornon-objections must be obtained from state and federal governmental authorities, including the Federal Deposit Insurance Corporation, the Board of Governors of the Federal Reserve System, the Commissioner of the Montana Division of Banking and Financial Institutions, and the Arizona Department of Financial Institutions. Satisfying the requirements of these governmental authorities may delay the date of completion of the merger. In addition, these governmental authorities may include conditions on the completion of the merger, or require changes to the terms of the merger. While Glacier and SBC do not currently expect that any such conditions or changes would result in a material adverse effect on Glacier, there can be no assurance that they will not, and such conditions or changes could have the effect of delaying completion of the merger, or imposing additional costs on or limiting the revenues of Glacier following the merger, any of which might have a material adverse effect on Glacier following the merger. The parties are not obligated to complete the merger should any required regulatory approval, waiver ornon-objection contain a condition or requirement not normally imposed in such transactions that, in the commercially reasonable and good faith opinion of Glacier’s board of directors, would deprive Glacier of the material economic or business benefits of the merger.

Risks Associated with Glacier’s Business

Glacier is, and will continue to be, subject to the risks described in Glacier’s Annual Report on Form10-K for the fiscal year ended December 31, 2018, as updated by a Quarterly Report on Form10-Q for the quarter ended June 30, 2019, and subsequent Current Reports on Form8-K, and Quarterly Reports on Form10-Q, all of which are filed with the SEC and incorporated by reference into this proxy statement/prospectus. See “References to Additional Information” and “Where You Can Find More Information” included elsewhere in this proxy statement/prospectus.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This document, including information included or incorporated by reference in this document may contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to,(i) statements about the benefits of the merger, including future financial and operating results, cost savings, enhancements to revenue and accretion to reported earnings that may be realized from the merger;(ii) statements about our respective plans, objectives, expectations and intentions and other statements that are not historical facts; and(iii) other statements identified by words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” “estimates,” or words of similar meaning. These forward-looking statements are based on current beliefs and expectations of management and are inherently subject to significant business, economic and competitive uncertainties and contingencies, many of which are beyond Glacier’s and FNB’sSBC’s control. In addition, these forward-looking statements are subject to assumptions with respect to future business strategies and decisions that are subject to change.

In addition to factors previously disclosed in Glacier’s reports filed with the SEC relating to risks to Glacier’s business and stock price, and those identified elsewhere in this document (including the section entitled “Risk Factors”), the following potential factors, among others, could cause actual results to differ materially from the anticipated results or other expectations expressed or implied in the forward-looking statements:

All subsequent written and oral forward-looking statements concerning the proposed transaction or other matters attributable to Glacier or FNBSBC or any person acting on behalf of Glacier or FNBSBC are expressly qualified in their entirety by the cautionary statements above. Neither Glacier nor FNBSBC undertakes any obligation to update any forward-looking statements to reflect circumstances or events that occur after the date the forward-looking statements are made.

SELECTED HISTORICAL FINANCIAL INFORMATION OF GLACIER

The following table presents selected consolidated financial information of Glacier for the fiscal yearsperiods and dates indicated. This information has been derived from Glacier’s consolidated financial statements filed with the SEC. Historical data as of and for the six months ended December 31,June 30, 2019 and 2018 2017, 2016, 2015,are based upon unaudited financial statements and 2014.include, in the opinion of Glacier management, all normal recurring adjustments considered necessary to present fairly the results of operations and financial condition of Glacier. The consolidated financial data below should be read in conjunction with the consolidated financial statements and notes thereto, incorporated by reference in this proxy statement/prospectus. See “Where You Can Find More Information.”

COMPARATIVE STOCK PRICE AND DIVIDEND INFORMATION

Glacier Common Stock

Glacier common stock is quoted on The NASDAQ Global Select Market under the symbol “GBCI.” The following table sets forth for the periods indicated:

At March 11,[], 2019, the 84,579,372[] outstanding shares of Glacier common stock were held by approximately 2,414[] holders of record.

FNBSBC Common Stock

FNBTrading in SBC’s common stock has not been extensive and such trades cannot be characterized as constituting an active trading market. SBC’s common stock is not listed on a stock market orany national securities exchange, although it is quoted on any“over-the-counter” marketthe OTC Pink under the ticker symbol “SBAZ.” The following table sets forth for the periods indicated:

At March 6,[], 2019, the 3,160,969[] outstanding shares of FNBSBC common stock were held by approximately 147[] holders of record.

FNBSBC SPECIAL SHAREHOLDERS’ MEETING

Date, Time, Place

The FNBSBC special meeting of shareholders will be held on April 18,[], 2019, at 10:00 a.m.[] [].m. Mountain Standard Time, at the Davis Conference Center located at 1651 North 700 West, Layton, Utah 84041.[], Lake Havasu City, Arizona.

As described below under “Votes Required and Quorum,” approval of the merger agreement requires the affirmative vote of at least a majority of the outstanding shares of FNB’s outstandingSBC’s common stock.stock entitled to vote on the matter. The proposal to adjourn the special meeting, if necessary or appropriate, including adjournments to solicit additional proxies, will be approved if the votes cast in favorapproved by a majority of the proposal exceed the votes cast against the proposal,voting power present, whether in person or by proxy, assuming a quorum is present. If less than a quorum is represented at the special meeting, a majority of the shares so represented may adjourn the special meeting without further notice.

Purpose

At the special meeting, FNBSBC shareholders will:

Record Date; Shares Outstanding and Entitled to Vote

The FNBSBC Board has fixed 5:00 p.m. Mountain Timethe close of business on March 6,[], 2019 as the record date for determining the holders of shares of FNBSBC common stock entitled to notice of and to vote at the special meeting. At the close of business on the record date, there were approximately 147[] holders of record and 3,160,969[] shares of FNBSBC common stock issued and outstanding.outstanding, excluding [] shares of unvested restricted stock, which do not have voting rights. Holders of record of FNBSBC common stock, excluding unvested restricted shares, on the record date are entitled to one vote per share and are also entitled to exercise dissenters’ rights if certain procedures are followed. See “The Merger – Dissenters’ Rights” andAppendix B.

FNB’sSBC’s directors and executive officers and certain significant shareholders have agreed to vote all shares of FNBSBC common stock they are entitled to vote that are held or controlled by them in favor of approval of the merger agreement. As of the record date, hereof, a total of 1,357,605[] shares of FNBSBC common stock, representing approximately 42.95%[]% of all outstanding shares of FNBSBC common stock, excluding shares of unvested restricted stock, are covered by thesubject to voting agreement.agreements. See “The Merger – Interests of FNBSBC Directors and Executive Officers in the Merger – Voting Agreement.Agreements.”

Votes Required and Quorum

The affirmative vote of the holders of at least a majority of the outstanding shares of FNB’s outstandingSBC’s common stock entitled to vote is required to approve the merger agreement. At least a majority of the total outstanding shares of FNBSBC common stock entitled to vote must be present, either in person or by proxy, in order to constitute a quorum for the special meeting. For purposes of determining a quorum, abstentions areand brokernon-votes will be counted in determining the shares present at a meeting.

For voting purposes, however, shares must be affirmatively votedFOR approval of the merger agreement in order to be counted as votes in favor of the merger. As a result, abstentions and brokernon-voteswith respect to the proposal to approve the merger agreement will have the same effect as votes against such proposal.

If less thanWith respect to the proposal to adjourn the special meeting if necessary or appropriate, if a quorum is representednot present at the special meeting, a majority ofshareholders entitled to vote at the shares so represented mayspecial meeting, present in person or by proxy, will have the power to adjourn the special meeting. If a quorum is present at the special meeting, without further notice. Thethe proposal to adjourn the special meeting, if necessary or appropriate, including adjournmentsan adjournment to solicit additional proxies in favor of the merger agreement, will be approved if the votes cast in favorapproved by a majority of the proposal exceedvoting power present at the votes cast against the proposal, assuming a quorum is present.special meeting, whether in person or by proxy.

Voting, Solicitation, and Revocation of Proxies

If you are a holder of record of SBC common stock as of the record date for the special meeting there are four ways to have your shares voted:

If the enclosed proxy card is duly executed and received in time for the special meeting, it will be voted in accordance with the instructions given. If the proxy card is duly executed and received but no instructions are given, it is the intention of the persons named in the proxy to vote the shares represented by the proxyFOR the approval of the merger agreement andFOR the proposal to approve one or more adjournments to solicit additional proxies, and in the proxy holder’s discretion on any other matter properly coming before the meeting. Any proxy given by a shareholder may be revoked before its exercise by:

FNBSBC is soliciting the proxy for the special meeting on behalf of the FNBSBC Board. FNBSBC will bear the cost of solicitation of proxies from its shareholders. In addition to using the mail, FNBSBC may solicit proxies by personal interview, telephone, and facsimile. Banks, brokerage houses, other institutions, nominees, and fiduciaries will be requested to forward their proxy soliciting material to their principals and obtain authorization for the execution of proxies. FNB does not expect to pay any compensation for the solicitation of proxies. However, FNBSBC will, upon request, pay the standard charges and expenses of banks, brokerage houses, other institutions, nominees, and fiduciaries for forwarding proxy materials to and obtaining proxies from their principals.

Voting in Person at the Special Meeting

Shares helddirectly in your name as the shareholder of record may be voted in person at the special meeting. If you choose to vote your shares of FNBSBC common stock in person, please bring the enclosed proxy card or proof of identification. Even if you plan to attend the special meeting, we recommend that you vote your shares of FNBSBC common stock in advance as described above so that your vote will be counted if you later decide not to attend the special meeting.

If your shares are registered in “street name” in the name of a broker or other nominee and you wish to vote at the special meeting, you will need to obtain a legal proxy from your bank or brokerage firm. Please consult the voting form sent to you by your bank or broker to determine how to obtain a legal proxy in order to vote in person at the meeting.

BACKGROUND OF AND REASONS FOR THE MERGER

Background of the Merger

From time to time, the FNBAs part of its ongoing consideration and evaluation of SBC’s long-term prospects and strategy, SBC’s Board of Directors and senior management have periodically reviewed and assessed strategic opportunities and challenges. The Board of Directors has discussed, analyzed and considered the valueprospects of continued growth and significanceoperating a financial institution under current economic, regulatory and competitive conditions. At the same time, like many other smaller financial institutions, SBC has experienced increasing costs related to technology and regulatory compliance.

As part of FNBthe Board of Directors’ and management’s evaluation of ways to its shareholders, customers,meet these challenges, they have met regularly with Davidson to review developments in the banking industry and employees,the equity markets generally, the mergers and acquisitions market, SBC’s financial performance relative to certain other financial institutions, capital management strategies and valuation trends. Davidson is a nationally recognized investment banking firm with substantial experience advising financial institutions generally, including with respect to mergers and acquisitions.

On July 9, 2018, the SBC Board held a meeting to evaluate a potential strategy for SBC to complete an initial public offering (“IPO”). Davidson and Hogan Lovells US LLP, SBC’s outside legal counsel (“Hogan”), also attended the meeting. The meeting included discussion regarding the requirements for being a public company, as well as the vital role it has playedbenefits and costs to be incurred if SBC decided to pursue an IPO strategy.

On November 29, 2018, the SBC Board held a strategic meeting as part of the Board’s ongoing assessment of SBC’s strategic opportunities and challenges. Representatives of Davidson and Hogan also attended the meeting. At the meeting, Hogan reviewed strategic planning guidelines and an overview of director responsibilities and conduct during the strategic planning process, and the Board reviewed and discussed with Hogan the Board’s fiduciary duties in a merger context. Davidson discussed with the Board developments in the local communitybanking industry, an update on the equity markets as well as valuations for over 110 years. In recent years, several bank holding companies have expressed interestpeer financial institutions and other financial institutions in pursuing a combination with FNB,general, the mergers and acquisition market and current valuation metrics. The discussion also included SBC’s desire to evaluate potential acquisition targets, and the limited number of viable acquisition targets remaining for SBC, especially in Arizona. Davidson also reviewed the merger and acquisition process and other merger considerations, including a list of potential strategic partners for SBC, which such list included Glacier. The SBC Board authorized Brian Riley to contact three parties, including Glacier and Parties A and B, to discuss the possibility of a merger and execute an NDA with the parties.

On December 5, 2018, Brian Riley contacted the CEO of equalsParty A. The parties executed a nondisclosure agreement on December 21, 2018, and an acquisition by a larger institution. As part of its responsibilityParty A was provided with access to consider these expressions of interest, the FNB Board engaged Sandler O’Neill in April of 2014 to provide strategic advisory services to FNB. The FNB Board considered each of the opportunities as they arose,certain confidential information for due diligence.

On December 12, 2018, Brian Riley contacted Glacier’s CEO. Mr. Riley previously met with Glacier’s CEO and each time the FNB Board ultimately determined that remaining independent was in the best interests of the shareholders they represented.

Like many other community banks, the FNB Board has strategized around a number of business issues including: increasing competition from bank andnon-bank institutions, continued allowance of regulatory overreach from local credit unions, heightened compliance and regulatory risk, succession planning around an aging management team, and maintaining loan growth in the face of rising real estate lending concentrations. At an FNB Board meetingSenior Executives in May of 2018, President2017 and Chief Executive Officer K. John Jones presented a shareholder value analysis. The FNB Board considered the analysis and its duty to maximize value for shareholders, as well its responsibility for maintaining the historic legacy of service to the local community, dedicated employees, and the loyal customer base. The FNB Board concluded that remaining independent was in the best interests of the shareholders but confirmed that that if FNB received a bona fide acquisition proposal that would reasonably be expected to result in a certain value for shareholders, that the FNB Board would need to seriously consider the proposal as an alternative to remaining independent, consistent with its fiduciary duty to the shareholders.

Following the FNB Board’s decision to remain independent, Mr. Jones contacted representatives of Sandler O’Neill in early JulySeptember of 2018 and terminated the existing engagement letter.

Later in July of 2018 the Chief Executive Officer of a bank holding company, which we refer to as Company A, met with FNB’s Chairman, Kevin Garn, to discuss business opportunitiesa potential strategic partnership. The parties decided to schedule a meeting in Kalispell, Montana for January 14, 2019, to further discuss a potential merger between Company A and FNB.the two companies. At thethis meeting, Company A’s Chief Executive Officer expressed his strongGlacier described interest in acquiring FNB and expressed Company A’s willingnessmerger discussions, but could not announce a transaction with SBC until the fourth quarter 2019, since Glacier was working on other pending acquisition opportunities which had not been publicly announced. The parties agreed to paypostpone further discussions on a significant merger premium. Followinguntil the meeting, Chairman Garn and Mr. Jones discussed the meeting with representativessummer of Sandler O’Neill and determined it was likely that Company A would make an acquisition proposal that would meet or exceed the threshold established by the FNB Board at its May 2018 meeting. Accordingly, Chairman Garn and Mr. Jones directed representatives of Sandler O’Neill to contact Company A to try to determine the maximum value that Company A would be willing to offer FNB in an acquisition proposal. As part of this discussion, Chairman Garn, Mr. Jones and representatives of Sandler O’Neill also discussed Glacier and two other potential acquirors and the potential values that they might be willing to offer FNB in an acquisition. Following this conversation, representatives of Sandler O’Neill were instructed to contact Glacier and two other bank holding companies, which we refer to as Company B and Company C, to gauge their interest in a possible acquisition of FNB.

Throughout August, representatives of Sandler O’Neill held conversations with Glacier, Company A and Company B about the potential acquisition of FNB. Company C had previously expressed interest in acquiring FNB but had now determined that it was not interested in pursuing acquisition discussions with FNB at that time. The conversations with Glacier, Company A and Company B included the sharing of publicly available information along with some high-level guidance on acquisition assumptions. In addition to the conversations with representatives of Sandler O’Neill, each of the companies met with Chairman Garn and Mr. Jones. In these meetings, Chairman Garn and Mr. Jones emphasized that FNB2019.

intendedOn January 29, 2019, Davidson received anon-binding indication of interest from Party A for 100% stock consideration. The SBC Board held a meeting on January 31, 2019, to remain independent,review the offer from Party A, along with Davidson and Hogan in attendance. After evaluating the offer, and discussing with Davidson and Hogan, the Board decided it would not pursue further discussion with Party A since the consideration value was below SBC’s expectations and more broader concerns with recent volatility in the stock market and impact on Party A’s stock price. Party A was notified and discussions were suspended on February 5, 2019.

On November 14, 2018, Brian Riley met with Party B for an informal discussion on general banking matters. In March and April 2019, SBC had communications with the CEO of Party B and revisited the idea of a strategic merger combination. SBC and Party B executed a nondisclosure agreement on April 26, 2019. Party B was provided with access to certain confidential information for due diligence.

On May 2, 2019, SBC executed an engagement letter with Davidson.

On May 7, 2019, Brian Riley and Glacier’s CEO held a discussion while attending the Davidson annual financial institutions conference. The parties discussed continued interest in a merger and Glacier provided an update on timing for a potential transaction to begin due diligence in July or August 2019, with an announcement in fourth quarter of 2019. On May 17, 2019, Glacier and SBC executed a nondisclosure agreement.

On May 7, 2019, Brian Riley and Party B’s CEO held a discussion while attending the Davidson annual financial institutions conference. The parties discussed continued interest in a merger, preliminary due diligence and timing for next steps.

On May 23, 2019, SBC received anon-binding indication of interest letter from Party B for 100% stock consideration. The offer also included a90-day period of exclusivity with Party B. The SBC Board held a meeting on May 30, 2019, to review the offer from Party B, with Davidson and Hogan in attendance. The SBC Board discussed the offer, and noted the SBC shareholders would retain a sizeable ownership percentage in the pro forma company. The SBC Board authorized Brian Riley and Davidson to continue negotiations with Party B.

On June 6, 2019, SBC and Party B executed a nonbinding indication of interest letter which included a45-day exclusivity period and provided for two (2) of SBC’s directors to join Party B’s Board of Directors. Subsequently, Party B and SBC immediately began due diligence and reverse due diligence, where confidential information was exchanged between the parties. As due diligence continued, SBC management expressed concerns about the integration risk and execution risk with Party B. The SBC Board discussed these concerns at the June 27, 2019, board meeting, but decided to continue its due diligence. SBC and Party B held anin-person meeting for due diligence in early July 2019 with representatives from Davidson and Hogan in attendance. Subsequent to this meeting, the SBC Board held a telephonic meeting to discuss the integration risk and execution risk and voted that it was no longer in the best interest of SBC shareholders to continue pursuing a merger with Party B.

On July 5, 2019, Brian Riley notified Party B that the SBC Board decided to terminate discussions with Party B, but SBC would seriously considerhonor the exclusivity period as agreed upon, which continued through July 21, 2019.

On June 18, 2019, Glacier contacted SBC to inform SBC the timing for a potential merger could be moved up. Davidson and SBC responded to Glacier that SBC had executed an acquisition proposal if it met certain criteria. Maximizing valueindication of interest with another party and was precluded to respond further due to the exclusivity period currently in effect.

On July 9, 2019, Glacier sent an unsolicited nonbinding indication of interest to SBC, which included per share consideration of 80% in Glacier stock and 20% in cash, plus additional cash for FNB shareholdersa dividend prior to closing. After SBC discussed with Hogan and Davidson, SBC instructed Davidson to inform Glacier that SBC received the letter, but SBC was of primary importance, but preserving FNB’s rich legacy, minimizing employee impact,bound to the exclusivity period with the other party, and continuingwill not discuss anything further with Glacier until the exclusivity period expired.

On July 11, 2019, Hogan sent a letter to supportinform Party B, as required by the local community were also important considerationsterms of the FNB Board.

On September 7, 2018 representativesexclusivity period in the indication of interest between Party B and SBC, that SBC received an unsolicited indication of interest from Glacier met with Chairman Garn, Mr. Jones and other members of the FNB executive team in Layton, Utah.

On September 14, 2018, Company B submitted anon-binding letter of intent outlining the proposed terms of third party (Glacier) for an acquisition of FNB for merger consideration comprisedSBC, but would honor the exclusivity period..

On July 21, 2019, the exclusivity period with Party B expired.

On July 22, 2019, SBC contacted Glacier and informed them that SBC would discuss the Glacier offer at the regularly scheduled SBC Board meeting on July 30, 2019.

On July 30, 2019, the SBC Board reviewed the nonbinding indication of 75% Company B common stockinterest from Glacier with Davidson and 25% cash. At that time, there was no public market for Company B’s common stock, but Company BHogan representatives in attendance. Davidson provided an estimateupdate of the valuemergers and acquisitions market and recent trends in merger market metrics for financial institutions, and discussed recent transactions involving peer institutions, the financial terms of Company B stock. Company B further indicatedthe indication of interest from Glacier in comparison to those metrics and in comparison to the expected future performance of SBC based upon information and projections provided by management. The Board reviewed the process and timeline that it was not preparedwould occur if the Board determined to proceed with a transaction immediately, but expected to be ready to commence due diligence andmerger. Davidson then reviewed in detail the negotiationindication of definitive merger documents during the first quarter of 2019.

On October 10, 2018, Glacier submitted anon-binding letter of intent outlining the principal terms for the proposed acquisition of FNB in exchange for Glacier common stock based on a fixed exchange ratio of 0.5770 Glacier shares in exchange for each share of FNB stock.

Also on October 10, 2018, Company A submitted anon-binding letter of intent outlining the principal terms for the proposed acquisition of FNB in exchange for Company A common stock, which was publicly traded, based on a fixed exchange ratio.

Representatives of Sandler O’Neill discussed thenon-binding letters of intent withinterest from Glacier, and Company AGlacier’s history and Company B, respectively, and provided additional information as requested.

On October 23, 2018, after review of additional information presented, Glacier submitted an updated letter of intent in which it increased the exchange ratio to 0.6652 Glacier shares in exchange for each share of FNB stock.

On October 28, 2018, the FNB Board met with representatives of Sandler O’Neill and legal counsel to discuss the threenon-binding letters of intent. An overall lower valuation and the lack of a public trading market for Company B’s stock made Company B’s proposal less desirable than the proposals from Company A and Glacier. Based on recent closing stock prices as of the meeting date, the value of Company A’s proposal was estimated at $27.32 per FNB share and the value of Glacier’s proposal was estimated at $26.84 per FNB share. The FNB Board considered the value of the proposals on that day and over the prior six months. The FNB Board reviewed the attributes of Glacier and Company A stock including valuation multiples, historical stock price performance, daily stock trading volume, quarterly cash dividends and institutional research analyst recommendations. The FNB Board reviewed the historical financial performance and acquisition track-recordtrading metrics. The SBC Board discussed the pricing offered, as well as Glacier’s intention to remain committed to community banking in Arizona, Glacier’s model for operating banking divisions and its desire for Brian Riley to serve as President and CEO of each of Glacier and Company A, recognizing the deal values for each would fluctuate on a daily basis. The FNB Board considered the strategic implications of the Glacier proposal andGlacier’s Arizona division, with the expectation that based on Glacier’s intentionthe business structure would limit disruption to create a new Utah division comprised of the operations of FNB’sSBC’s business and Glacier Bank’s Utah branches, it was expected that a merger with Glacier would have a limited impact on FNB’s employees. Additionally, the new division would be able to operate with a certain level of autonomy after the merger,SBC’s employees, customers and be better positioned to understand and serve the local community. In contrast, the FNB Board expected that Company A’s proposal would result in more employee job loss and a potential disruption to FNB’s business. The FNB Board considered the proposals against FNB’s expected performance on a stand-alone basis.communities. After considering all three proposalsGlacier’s proposal, the SBC Board indicated it was interested in a merger with Glacier, and evaluating FNB’s stand-alone prospects, the FNB Board concluded that the Glacier proposal was superiorinstructed Davidson to the other alternatives. Glacier’s long-term stock, dividend performance, stock trading liquidity, community banking modelrespond to Glacier. Between July 31 and proposal to continue

On January 10,September 19, 2019, the FNBSBC Board, together with representatives of Sandler O’NeillDavidson and legal counsel,Hogan, met to consider Glacier’s due diligence findings, the reduced exchange ratio and the proposed definitive merger agreement as negotiated to date. Representatives of Sandler O’NeillDavidson reviewed the financial aspects of the proposed merger. FNB’s legal counselHogan reviewed the specific terms of the merger agreement and the substantial process involved in negotiating its terms. The FNBSBC Board considered all these matters and determined that the reduced offer still constituted s significant premium and unanimously confirmed its desire to proceedcontinue with negotiations of the proposed merger.

On January 11, 2019, FNB management conducted onsite diligence at Glacier’s headquarters.

On January 15,September 30, 2019, the FNBSBC Board, together with representatives of Sandler O’NeillDavidson and legal counsel,Hogan, again met to consider the negotiated proposed definitive merger agreement. Hogan reviewed the terms of the proposed merger agreement and the changes to the proposed merger agreement since the SBC Board’s September 19, 2019, meeting, and all related ancillary agreements. Representatives of Sandler O’NeillDavidson then reviewed the financial aspects of the proposed merger and rendered to the FNB BoardSBC a verbal fairness opinion, which was subsequently confirmed in writing, to the effect that, as of that date and subject to the procedures followed, assumptions made, matters considered and qualifications and limitations on the review undertaken by Sandler O’Neill,Davidson, the merger consideration in the proposed merger with Glacier was fair, from a financial point of view, to the holders of FNBSBC common stock. Legal counsel then reviewed the terms of the proposed merger agreement and the changes to the proposed merger agreement since the FNB Board’s January 10 meeting. Among other matters considered, the FNBSBC Board reviewed

Opinion of SBC’s Financial Advisor

On May 2, 2019, SBC entered into an engagement agreement with D.A. Davidson & Co. to render financial advisory and investment banking services to SBC. As part of its engagement, Davidson agreed to assist SBC in analyzing, structuring, negotiating and, if appropriate, effecting a transaction between SBC and another corporation or business entity. Davidson also agreed to provide the reasons that ledSBC Board with an opinion as to the FNB Board to approve the merger agreement and recommend that FNB’s shareholders vote in favorfairness, from a financial point of view, of the merger agreement is not intendedconsideration to be exhaustive but is believed to include all of the material reasons for the FNB Board’s decision. In reaching its determination to approve and recommend the transaction, the FNB Board based its recommendation on the totality of the information presented to it and did not assign any relative or specific weightspaid to the reasons considered in reaching that determination. Individual directors may have given differing weights to different reasons. After deliberating with respect to the merger with Glacier, considering, among other things, the matters discussed above, the FNB Board unanimously approved the merger agreement and the merger with Glacier as beingholders of SBC common stock in the best interests of FNB and its shareholders.

Opinion of FNB’s Financial Advisor

FNB retained Sandler O’Neill to act as an independent financial advisor to FNB’s board of directors in connection with FNB’s consideration of a possible business combination. Sandler O’Neillproposed merger. SBC engaged Davidson because Davidson is a nationally recognized investment banking firm whose principal business specialtywith substantial experience in transactions similar to the merger and is financial institutions. In the ordinary coursefamiliar with SBC and its business. As part of its investment banking business, Sandler O’NeillDavidson is regularlycontinually engaged in the valuation of financial institutions and their securities in connection with mergers and acquisitions and other corporate transactions.

Sandler O’Neill acted as an independent financial advisor in connection withOn September 30, 2019, the SBC Board held a meeting to evaluate the proposed transaction and participated in certainmerger. At this meeting, Davidson reviewed the financial aspects of the negotiations leadingproposed merger and rendered an opinion to the execution of the merger agreement. At the January 15, 2019 meeting at which FNB’s board of directorsSBC Board that, as such date and based upon and subject to assumptions made, procedures followed, matters considered and discussedlimitations on the terms of the merger agreement and the merger, Sandler O’Neill delivered to FNB’s board of directors its oral opinion, which was subsequently confirmed in writing, to the effect that, as of January 15, 2019,review undertaken, the merger consideration provided for in the merger agreement was fairto be paid to the holders of FNBSBC common stock was fair, from a financial point of view.view, to such holders of SBC common stock in the proposed merger.

The full text of Sandler O’Neill’sDavidson’s written opinion, dated September 30, 2019, is attached as Appendix C to this proxy statement/prospectus. The opinion outlines the procedures followed, assumptions made, matters consideredstatement-prospectus and qualifications and limitations on the review undertakenis incorporated herein by Sandler O’Neill in rendering its opinion.reference. The description of the opinion set forth belowherein is qualified in its entirety by reference to the full text of thesuch opinion. Holders of FNB common stockSBC’s shareholders are urged to read the entire opinion carefully in connection with their consideration of the proposed merger.

Davidson did not make an independent evaluation or perform an appraisal of the loan and lease portfolios, classified loans, other real estate owned or any other specific assets, the collateral securing assets or the liabilities (contingent or otherwise) of FNB or GBCI or any of their respective subsidiaries, nor was Sandler O’Neill furnished with any such evaluations or appraisals. Sandler O’Neill rendered no opinion or evaluation on the collectability of any assets or the future performance of any loans of FNB or GBCI. Sandler O’Neill did not make an independent evaluation ofhas Davidson assessed the adequacy of the allowance for loan losses of FNBSBC or GBCI, or of the combined entity after the merger, and Sandler O’Neill didGlacier. Davidson has not reviewreviewed any individual credit files relating to FNBSBC or GBCI. Sandler O’NeillGlacier. Davidson assumed with the consent of FNB, that the respective allowances for loan losses for both FNBSBC and GBCI wereare adequate to cover such losses and wouldwill be adequate on a pro forma basis for the combined entity.

In preparing its analyses, Sandler O’Neill used internal net income projections for FNB for Davidson did not make an independent evaluation of the years ending December 31, 2018 through December 31, 2020 withquality of SBC’s or Glacier’s deposit base, nor have we independently evaluated potential deposit concentrations or the deposit composition of SBC or GBCI. Davidson did not make an annual net income growth rate forindependent evaluation of the years thereafter, as provided by the senior managementquality of FNB, as well as estimated dividends per share for the years ending December 31, 2018 through December 31, 2022, as directed by the senior management of FNB. In addition, Sandler O’Neill used publicly available consensus analyst earnings per share estimates for GBCI for the years ending December 31, 2018 through December 31, 2020, as well as a long-term earnings per share growth rate for the years thereafter and dividend payout ratio for the years ending December 31, 2018 through December 31, 2022, as directed by the senior management of GBCI. Sandler O’Neill also received and used in its pro forma analyses certain assumptions relating to purchase accounting adjustments, cost savings and transaction expenses, as provided by the senior management of GBCI. With respect to the foregoing information, the respective senior managements of FNB and GBCI confirmed to Sandler O’Neill that such information reflected (or,SBC’s or Glacier’s investment securities portfolio, nor have we independently evaluated potential concentrations in the caseinvestment securities portfolio of the publicly available consensus analyst estimates referred to above, were consistent with) the best currently available projections, estimates and judgments of those respective managements as to the future financial performance of FNB and GBCI, respectively, and the other matters covered thereby, and Sandler O’NeillSBC or Glacier.

Davidson assumed that the future financial performance reflectedall representations and warranties contained in such information would be achieved. Sandler O’Neill expressed no opinion as to such information, or the assumptions on which such information was based. Sandler O’Neill also assumed that there had been no material change in the respective assets,

In performing its analyses, Sandler O’Neill also made numerous assumptions with respect to industry performance, business and economic conditions and various other matters, many of which are beyond the control of FNB, GBCI and Sandler O’Neill. The analyses performed by Sandler O’Neill are not necessarily indicative of actual values or future results, both of which may be significantly more or less favorable than suggested by such analyses. Sandler O’Neill prepared its analyses solelyImplied Valuation Multiples for purposes of rendering its opinion and provided such analyses to FNB’s board of directors at its January 15, 2019 meeting. EstimatesSBC based on the values of companies do not purport to be appraisals or necessarily reflect the prices at which companies or their securities may actually be sold. Such estimates are inherently subject to uncertainty and actual values may be materially different. Accordingly, Sandler O’Neill’s analyses do not necessarily reflect the value of FNB common stock or the prices at which FNB common stock or GBCI common stock may be sold at any time. The analyses of Sandler O’Neill and its opinion were among a number of factors taken into consideration by FNB’s board of directors in making its determination to approve the merger agreement and should not be viewed as determinative of the exchange ratio or the decision of FNB’s board of directors or management with respect to the fairness of the merger. The type and amount of consideration payable in the merger were determined through negotiation between FNB and GBCI.Merger Consideration

Summary of Exchange Ratio and Implied Transaction Metrics. Sandler O’NeillDavidson reviewed the financial terms of the proposed merger. Subject to certain adjustments and termination provisions, as more fullytransaction. As described in the merger agreement, at the effective time, each share of FNBSBC common stock issued and outstanding prior to the effective time, except for certain shares of FNB common stock as specified in the merger agreement, will be converted into the right to receive 0.64740.3706 shares of GBCI common stock. BasedGlacier Common Stock and $1.69 in cash. The terms and conditions of the merger are more fully described in the merger agreement. For purposes of the financial analyses described below, based on the closing price of GBCIGlacier common stock on January 14,September 27, 2019, of $41.66, Sandler O’Neill calculated$40.43, the merger consideration represented an implied transaction pricevalue of $16.67 per share of FNBSBC common stock, of $26.97 and an aggregate implied transaction value of approximately $85.3or $135.3 million in exchange for all FNB common stock issued and outstanding as of January 14, 2019.aggregate. Based upon historical financial information for FNB as of or for the twelve month period ended June 30, 2019 and other financial and market information described below, Davidson calculated the following transaction ratios:

Stock Price Performance of SBC and GBCI

Davidson reviewed the history of the reported trading prices and volume of SBC and Glacier common stock and certain stock indices, including the Russell 3000 and the KBW Regional Bank Index. Davidson compared the stock price performance of SBC or Glacier with the performance of the Russell 3000 and the KBW Nasdaq Regional Bank Index as follows:

Contribution Analysis

Davidson analyzed the relative contribution of SBC and Glacier to certain financial and operating metrics for the pro forma combined company. Such financial and operating metrics included: (i) market capitalization; (ii) net income during the preceding twelve months ending June 30, 2019; (iii) projected net income in 2019 for Glacier based on average Street EPS estimates as discussed with and confirmed by GBCI and SBC management, and projected net income in 2019 for SBC as provided by and discussed with SBC management; (iv) total assets; (v) gross loans; (vi) total deposits; and (vii) tangible common equity. The relative contribution analysis did not give effect to the impact of any synergies as a result of the proposed merger. The results of this analysis are summarized in the table below, which also compares the results of this analysis with the implied pro forma ownership percentages of SBC or Glacier shareholders in the combined company based on the merger consideration, and also hypothetically assuming 100% stock consideration in the proposed merger:

Glacier Comparable Companies Analysis – Group One

Davidson used publicly available information to compare selected financial and market trading information for Glacier and 12 financial institutions selected by Davidson which: (i) were headquartered in Arizona, California, Colorado, Idaho, Montana, North Dakota, Nevada, New Mexico, Oregon, South Dakota, Utah, Washington or Wyoming; (ii) had their common stock listed on the NASDAQ or NYSE; (iii) had assets between $7.5 billion and $30.0 billion; and (iv) were not pending merger targets or ethnic-focused banks. These 12 financial institutions were as follows:

Note: Does not reflect impact from pending acquisitions or acquisitions closed after September 27, 2019

The analysis compared the financial condition and market performance of Glacier and the 12 financial institutions identified above based on publicly available financial and market trading information for Glacier and the 12 financial institutions as of and for the twelve-month or three-month period ended June 30, 20182019. The analysis also compared the 2019 and internal2020 earnings per share multiples for Glacier and the 12 financial institutions identified above based on average Street EPS estimates for FNBGlacier and the 12 financial institutions. The table below shows the results of this analysis (excluding the impact of earnings per share multiples considered not meaningful by Davidson).

Glacier Comparable Companies Analysis – Group Two

Davidson used publicly available information to compare selected financial and market trading information for Glacier and 19 financial institutions selected by Davidson which: (i) were headquartered in nationwide; (ii) had their common stock listed on the NASDAQ or NYSE; (iii) had assets between $7.5 billion and $30.0 billion; (iv) had return on average assets above 1.50% for the year ending December 31,last twelve months; and (v) were not pending merger targets or ethnic-focused banks. These 19 financial institutions were as follows:

Note: Does not reflect impact from pending acquisitions or acquisitions closed after September 27, 2019

The analysis compared the financial condition and market performance of Glacier and the 19 financial institutions identified above based on publicly available financial and market trading information for Glacier and the 19 financial institutions as providedof and for the twelve-month or three-month period ended June 30, 2019. The analysis also compared the 2019 and 2020 earnings per share multiples for Glacier and the 19 financial institutions identified above based on average Street EPS estimates for Glacier and the 19 financial institutions. The table below shows the results of this analysis (excluding the impact of earnings per share multiples considered not meaningful by Davidson).