As filed with the Securities and Exchange Commission on October 12, 1999
                                                      Registration No. 333-86547

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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                ---------------

                              Amendment No. 2
                                       to
                                    FORM S-1
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933

                                ---------------
                              Pennaco Energy, Inc.
             (Exact name of registrant as specified in its charter)
         Nevada                       1311                    88-0384598
    (State or other       (Primary Standard Industrial     (I.R.S. Employer
    jurisdiction of
    incorporation or      Classification Code Number)   Identification Number)
     organization)

                                ---------------
                          1050 17th Street, Suite 700
                             Denver, Colorado 80265
                                 (303) 629-6700
    (Address, including zip code, and telephone number, including area code,
                  of Registrant's principal executive offices)

                                 Paul M. Rady,
                     President and Chief Executive Officer
                              Pennaco Energy, Inc.
                          1050 17th Street, Suite 700
                             Denver, Colorado 80265
                                 (303) 629-6700
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                                   Copies to:
              David P. Oelman                        Robert A. Zuccaro
          Andrews & Kurth L.L.P.                     Latham & Watkins
          600 Travis, Suite 4200                     885 Third Avenue
           Houston, Texas 77002                  New York, New York 10022
              (713) 220-4200                          (212) 906-1200

      Approximate date of commencement of the proposed sale to the public:
As soon as practicable after the effective date of this Registration Statement.

                                ---------------
   If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act,
other than securities offered only in connection with dividend or interest
reinvestment plans, 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 earlier effective
registration statement for the same offering. [_]
   If this Form is a post-effective amendment filed pursuant to Rule 462(c)
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.  [_]
   If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [_]

                                ---------------
   The registrant hereby amends this registration statement on such date or
dates as may be necessary to delay its effective date until the registrant
shall file a further amendment which specifically states that this registration
statement shall thereafter become effective in accordance with Section 8(a) of
the Securities Act of 1933 or until the registration statement shall become
effective on such date as the Commission, acting pursuant to said Section 8(a),
may determine.

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                             EXPLANATORY NOTE

   This Amendment No. 2 to Pennaco Energy's Form S-1 is being filed to:

     1. Include a copy of the prospectus supplement dated October 12, 1999;
  and

     2. File a previously omitted exhibit.

                                       1



               SUBJECT TO COMPLETION, DATED OCTOBER 11, 1999

PROSPECTUS SUPPLEMENT

(To preliminary prospectus dated September 28, 1999)

   This prospectus supplement supplements the preliminary prospectus dated
September 28, 1999 of Pennaco Energy, Inc., relating to the public offering and
sale of 2,000,000 shares of common stock, par value $.001, by Pennaco and
1,000,000 shares of common stock by the selling stockholder. This prospectus
supplement should be read with the preliminary prospectus.


 Recent Developments

   As of October 11, 1999, Pennaco's net working interest gas production has
increased to 21 million cubic feet, or MMcf, per day from approximately 100
producing wells located in the South Gillette Area in our Powder River Basin
coal bed methane project. Our production has increased from the previously
reported 11 MMcf per day due to the opening of KN Energy's Coal Searn Booster
Compressor Station in the South Gillette Area.


                                    PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 13. Other Expenses of Issuance and Distribution

   The expenses of the offering are estimated to be as follows:


                                                                    
      SEC Registration Fee............................................ $ 11,330
      Printing Expenses...............................................  100,000
      Legal Fees and Expenses.........................................  100,000
      Accounting Fees and Expenses....................................   10,000
      NASD Fee........................................................    4,011
      Miscellaneous...................................................  104,659
                                                                       --------
        TOTAL......................................................... $330,000
                                                                       ========


Item 14. Indemnification of Directors and Officers

   The Nevada Revised Statutes and certain provisions of the Company's Bylaws
under certain circumstances provide for indemnification of the Company's
officers, directors and controlling persons against liabilities that they may
incur in such capacities. A summary of the circumstances in which such
indemnification is provided for is contained herein, but this description is
qualified in its entirety by reference to the Company's Bylaws and to the
statutory provisions.

   In general, any officer, director, employee or agent may be indemnified
against expenses, fines, settlements or judgments arising in connection with a
legal proceeding to which such person is a party, if that person's actions were
in good faith, were believed to be in the Company's best interest, and were not
unlawful. Unless such person is successful upon the merits in such an action,
indemnification may be awarded only after a determination by independent
decision of the Board of Directors, by legal counsel, or by a vote of the
stockholders, that the applicable standard of conduct was met by the person to
be indemnified.

   The circumstances under which indemnification is granted in connection with
an action brought on behalf of the Company is generally the same as those set
forth above; however, with respect to such actions, indemnification is granted
only with respect to expenses actually incurred in connection with the defense
or settlement of the action. In such actions, the person to be indemnified must
have acted in good faith and in a manner believed to have been in the Company's
best interest, and must not have been adjudged liable for negligence or
misconduct.

   Indemnification may also be granted pursuant to the terms of agreements that
may be entered in the future or pursuant to a vote of stockholders or
directors. The statutory provision cited above also grants the power to the
Company to purchase and maintain insurance which protects its officers and
directors against any liabilities incurred in connection with their service in
such a position, and such a policy may be obtained by the Company.

Item 15. Recent Sales of Unregistered Securities.

   Set forth below is certain information concerning all sales of securities by
the Company during the past three years that were not registered under the
Securities Act.

   (a) The Company issued 995,000 shares of common stock in January 1998
pursuant to a share-for-share exchange with the stockholders of International
Metal Protection, Inc. in a transaction conducted solely to

                                      II-1


reincorporate the Company in a new jurisdiction. This transaction was exempt
from the registration requirements of the Securities Act pursuant to Section
4(2) of the Securities Act. There was no change in ownership and the
stockholders made no significant investment decision.

   (b) The Company issued 500,000 shares of common stock in February 1998 for
the purchase price of $.10 per share pursuant to a private placement exempt
from the registration requirements of the Securities Act pursuant to Section
4(2) of the Securities Act. Proceeds to the Company were approximately $50,000.
At that time, the Company had only a business plan and no assets. There were
eleven offerees in this offering, all of whom made purchases and all of whom
were sophisticated investors. The Company fully apprised each of the offerees
of the Company's start-up nature and gave them full details regarding the
Company's business plan. There was no general solicitation or advertising used
in connection with the offer to sell or sale of these securities. The
purchasers were advised that the securities, once purchased, could not be
resold or otherwise transferred without subsequent registration under the
Securities Act. Each purchaser represented to the Company that they were
purchasing the securities for their own account for investment purposes only.

   (c) The Company issued 4,530,000 shares of common stock in February 1998 for
a purchase price of $.22 per share pursuant to a Regulation D, Rule 504
offering. Proceeds to the Company were approximately $997,000. Offerees were
provided with a private placement memorandum containing detailed information
about the Company and its plan. The Company required each prospective investor
to represent in writing that (i) they had adequate means of providing for their
current needs and personal contingencies and had no need to sell the securities
in the foreseeable future and (ii) they, either alone or with their duly
designated purchaser representative, had such knowledge and experience in
business and financial matters that they were capable of evaluating the risks
and merits of an investment in the securities.

   (d) The Company issued 5,000,000 shares of common stock in April 1998 for a
purchase price of $1.25 per share pursuant to a Regulation D, Rule 506
offering. Proceeds to the Company were $6,250,000. The Company accepted
subscriptions only from accredited investors. Offerees were provided with a
private placement memorandum containing detailed information about the Company
and its plan. The Company required each prospective investor to represent in
writing that (i) they had received and reviewed the private placement
memorandum and understood the risks of an investment in the Company; (ii) they
had the experience and knowledge with respect to similar investments which
enabled them to evaluate the merits and risks of such investment, or they had
obtained and relied upon an experienced independent adviser with respect to
such evaluation; (iii) they had adequate means to bear the economic risk of
such investment, including the loss of the entire investment; (iv) they had
adequate means to provide for their current needs and possible personal
contingencies; (v) they had no need for liquidity of their investment in the
Company; (vi) they understood that the securities had not been registered under
the Securities Act and may have not been registered or qualified under
applicable state securities laws and, therefore, that they could not sell or
transfer the securities unless the securities were subsequently registered or
an exemption therefrom was available to them; (vii) they were acquiring the
securities for investment solely for their own account and without any
intention of reselling or distributing them; and (viii) they understood that
the securities would bear a restrictive legend prohibiting transfers except in
compliance with the provisions of the securities, the subscription agreement
executed by the purchaser and the applicable federal and state securities laws.

   (e) The Company issued 128,000 common stock purchase warrants with an
exercise price of $1.25 per share, exercisable after April 15, 1999 through
April 15, 2000, to Yorkton in April 1998 pursuant to a private placement
exemption from the registration requirements of the Securities Act under
Section 4(2) of the Securities Act. These warrants were issued pursuant to a
negotiated transaction between the Company and Yorkton, whereby Yorkton agreed
to provide corporate finance services to the Company for one year in return for
these warrants.

   (f) The Company issued 2,000,000 shares of common stock in June 1998 to RIS
pursuant to a Regulation D, Rule 506 offering for a purchase price of $1.75 per
share. Proceeds to the Company were approximately

                                      II-2


$3,500,000. The Company accepted subscriptions only from accredited investors.
Offerees were provided with a private placement memorandum containing detailed
information about the Company and its plan. The Company required each
prospective investor to represent in writing that (i) they had received and
reviewed the private placement memorandum and understood the risks of an
investment in the Company; (ii) they had the experience and knowledge with
respect to similar investments which enabled them to evaluate the merits and
risks of such investment, or they had obtained and relied upon an experienced
independent adviser with respect to such evaluation; (iii) they had adequate
means to bear the economic risk of such investment, including the loss of the
entire investment; (iv) they had adequate means to provide for their current
needs and possible personal contingencies; (v) they had no need for liquidity
of their investment in the Company; (vi) they understood that the securities
had not been registered under the Securities Act and may have not been
registered or qualified under applicable state securities laws and, therefore,
that they could not sell or transfer the securities unless the securities were
subsequently registered or an exemption therefrom was available to them; (vii)
they were acquiring the securities for investment solely for their own account
and without any intention of reselling or distributing them; and (viii) they
understood that the securities would bear a restrictive legend prohibiting
transfers except in compliance with the provisions of the securities, the
subscription agreement executed by the purchaser and the applicable federal and
state securities laws.

   (g) The Company issued 796,429 units in June, July and September 1998
pursuant to a Regulation D, Rule 506 offering to three members of the
management team of the Company, for a purchase price of $1.75 per unit, each
unit consisting of one share of common stock and one common stock purchase
warrant for every two shares purchased. All units were purchased by three
members of the management team of the Company. The warrants have an exercise
price of $1.75 per share in the first year and $1.96 per share in the second
year and are exercisable until September 4, 2000. Proceeds to the Company were
approximately $1,394,000. Offerees were provided with a private placement
memorandum containing detailed information about the Company and its plan. The
Company required each prospective investor to represent in writing that (i)
they had received and reviewed the private placement memorandum and understood
the risks of an investment in the Company; (ii) they had the experience and
knowledge with respect to similar investments which enabled them to evaluate
the merits and risks of such investment, or they had obtained and relied upon
an experienced independent adviser with respect to such evaluation; (iii) they
had adequate means to bear the economic risk of such investment, including the
loss of the entire investment; (iv) they had adequate means to provide for
their current needs and possible personal contingencies; (v) they had no need
for liquidity of their investment in the Company; (vi) they understood that the
securities had not been registered under the Securities Act and may have not
been registered or qualified under applicable state securities laws and,
therefore, that they could not sell or transfer the securities unless the
securities were subsequently registered or an exemption therefrom was available
to them; (vii) they were acquiring the securities for investment solely for
their own account and without any intention of reselling or distributing them;
and (viii) they understood that the securities would bear a restrictive legend
prohibiting transfers except in compliance with the provisions of the
securities, the subscription agreement executed by the purchaser and the
applicable federal and state securities laws.

   (h) The Company issued 1,215,000 units on September 4, 1998 pursuant to a
Regulation D, Rule 506 offering for a purchase price of $3.25 per unit, each
unit consisting of one share of common stock and one common stock purchase
warrant for every two shares purchased. The warrants had an exercise price of
$5.00 per share and expired on March 4, 1999. Proceeds to the Company were
approximately $3,900,000. The Company accepted subscriptions only from
accredited investors. Offerees were provided with a private placement
memorandum containing detailed information about the Company and its plan. The
Company required each prospective investor to represent in writing that (i)
they had received and reviewed the private placement memorandum and understood
the risks of an investment in the Company; (ii) they had the experience and
knowledge with respect to similar investments which enabled them to evaluate
the merits and risks of such investment, or they had obtained and relied upon
an experienced independent adviser with respect to such evaluation; (iii) they
had adequate means to bear the economic risk of such investment, including the
loss of the entire investment; (iv) they had adequate means to provide for
their current needs and possible personal contingencies; (v) they had no need
for liquidity of their investment in the Company; (vi) they

                                      II-3


understood that the securities had not been registered under the Securities Act
and may have not been registered or qualified under applicable state securities
laws and, therefore, that they could not sell or transfer the securities unless
the securities were subsequently registered or an exemption therefrom was
available to them; (vii) they were acquiring the securities for investment
solely for their own account and without any intention of reselling or
distributing them; and (viii) they understood that the securities would bear a
restrictive legend prohibiting transfers except in compliance with the
provisions of the securities, the subscription agreement executed by the
purchaser and the applicable federal and state securities laws. Yorkton served
as placement agent for this private placement. As compensation, Yorkton
received share purchase warrants to purchase 75,200 shares at an exercise price
of $3.58. These share purchase warrants were issued pursuant to the same
Regulation D, Rule 506 offering.

   Under the terms of a related escrow agreement, $763,750 in proceeds was
deposited into an interest bearing escrow account together with certificates
representing 235,000 units. The shares and the shares of common stock
underlying the warrants were to be registered for resale under the Securities
Act of 1993 with the U.S. Securities and Exchange Commission by December 31,
1998. The Company also agreed to have the shares qualified by way of an
exemption order provided by the respective Securities Commissions in Canada
by December 31, 1998. The registration statement has not been declared
effective. Accordingly, as of December 31, 1998, the subscriber may elect to
either purchase the escrow units or receive a refund from the escrow account
paid with their subscription, plus interest thereon, and an additional unit for
each ten units purchased in the offering. On February 28, 1999 all but one of
the subscribers elected to receive an additional unit for each ten units
purchased in the offering and, as a result, an additional 121,500 units are to
be issued. The subscriber is also entitled to receive an additional unit for
each ten units previously acquired in the offering in the event that the
Company does not maintain an effective registration statement until such time
as the registered securities may be resold pursuant to Rule 144 promulgated
under the Act.

   (i) The Company issued 90,000 common stock purchase warrants with an
exercise price of $4.72 per share, to SMS Operating, LLC under a private
placement exemption from the registration requirements of the Securities Act
under Section 4(2) of the Securities Act. These warrants were issued pursuant
to a negotiated transaction between the Company and SMS, whereby the Company
acquired certain lease acreage from SMS partially in exchange for the warrants.

Item 16. Exhibits.



 Exhibit No. Title
 ----------- -----
          
    *1.1     Form of Underwriting Agreement
    +3.1     Amended and Restated Articles of Incorporation
     3.2     Bylaws (filed as Exhibit 3.2 to the Company's Form 10-SB File No.
             00-24881, filed September 15, 1998 and included herein by
             reference)
     4.1     Form of Warrant (filed as Exhibit 4.1 to the Company's Form SB-2
             File No. 333-68317, filed December 3, 1998 and included herein by
             reference)
    +5.1     Opinion of Kummer Kaempfer Bonner & Renshaw
    10.1     Mineral Lease Purchase Agreement dated February 23, 1998 between
             High Plains Associates, Inc. and Pennaco Energy, Inc. (filed as
             Exhibit 10.1 to the Company's Form 10-SB/A File No. 00-24881,
             filed September 15, 1998 and included herein by reference)
    10.2     Letter Agreement dated January 23, 1998 between High Plains
             Associates, Inc. and Taylor Oil Properties (filed as Exhibit 10.2
             to the Company's Form 10-SB/A File No. 00-24881, filed September
             15, 1998 and included herein by reference)
    10.3     Assignment of Option and Exercise of Option dated March 6, 1998
             between High Plains Associates, Inc. and Pennaco Energy, Inc.
             (filed as Exhibit 10.3 to the Company's Form 10-SB/A File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.4     Agreement dated March 6, 1998 between High Plains Associates, Inc.
             and Pennaco Energy, Inc. (filed as Exhibit 10.4 to the Company's
             Form 10-SB/A File No. 00-24881, filed September 15, 1998 and
             included herein by reference)


                                      II-4




 Exhibit No. Title
 ----------- -----
          
    10.5     Pennaco Energy, Inc. 1998 Stock Option and Incentive Plan (filed
             as Exhibit 10.5 to the Company's Form 10-SB, File No. 00-24881,
             filed September 15, 1998 and included herein by reference)
    10.6     Form of Pennaco Energy, Inc. Incentive Stock Option Agreement
             (filed as Exhibit 10.6 to the Company's Form 10-SB, File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.7     Form of Pennaco Energy, Inc. Non-Statutory Stock Option Agreement
             (filed as Exhibit 10.7 to the Company's Form 10-SB, File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.8     Employment Agreement dated June 10, 1998 between Pennaco Energy,
             Inc. and Paul M. Rady (filed as Exhibit 10.8 to the Company's Form
             10-SB, File No. 00-24881, filed September 15, 1998 and included
             herein by reference)
    10.9     Employment Agreement dated July 2, 1998 between Pennaco Energy,
             Inc. and Glen C. Warren, Jr. (filed as Exhibit 10.9 to the
             Company's Form 10-SB, File No. 00-24881, filed September 15, 1998
             and included herein by reference)
    10.10    Secured Promissory Note dated August 13, 1998 from Pennaco Energy,
             Inc. to Venture Capital Sourcing, SA (filed as Exhibit 10.10 to
             the Company's Form 10-SB/A File No. 00-24881, filed September 15,
             1998 and included herein by reference)
    10.11    Second Amendment to Security Agreement dated August 13, 1998
             between Pennaco Energy, Inc. and Venture Capital Sourcing, SA
             (filed as Exhibit 10.11 to the Company's Form 10-SB/A File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.12    Purchase and Sale Agreement between Pennaco Energy, Inc., as
             Seller and CMS Oil and Gas Company, as Buyer, dated October 23,
             1998 (filed as Exhibit 10.12 to the Company's Form 10-SB, File No.
             00-24881, filed September 15, 1998 and included herein by
             reference)
    10.13    Secured Promissory Note dated October 23, 1998 from Pennaco
             Energy, Inc. to CMS Oil and Gas Company (filed as Exhibit 10.13 to
             the Company's Form 10-SB, File No. 00-24881, filed November 24,
             1998 and included herein by reference)
    10.14    Sublease Agreement dated October 23, 1998 between Pennaco Energy,
             Inc. and Evansgroup, Inc. (filed as Exhibit 10.14 to the Company's
             Form 10-SB/A File No. 00-24881 filed December 22, 1998 and
             included here by reference)
    10.15    Agreement Regarding the Drilling of Coal Bed Methane Wells (filed
             as Exhibit 10.15 to the Company's Form 10-SB/A File No. 00-24881,
             filed December 22, 1998 and included herein by reference)
    10.16    First Amendment to Purchase and Sale Agreement dated November 20,
             1998 (filed as Exhibit 10.16 to the Company's Form 10-SB/A File
             No. 00-24881, filed January 28, 1999 and included herein by
             reference)
    10.17    Second Amendment to Purchase and Sale Agreement dated January 15,
             1999 (filed as Exhibit 10.17 to the Company's Form 10-SB/A File
             No. 00-24881, filed January 28, 1999 and included herein by
             reference)
    10.18    Gas Gathering Agreement between Bear Paw Energy, Inc. and Pennaco
             Energy, Inc. dated February 1, 1999 (Portions of this Gas
             Gathering Agreement have been omitted based upon a request for
             confidential treatment. Additionally, the omitted portions have
             been filed with the SEC.) Filed as Exhibit 10.18 to the Company's
             Form SB-2 (Reg. No. 333-68317) and included herein by reference
    10.19    Gas Gathering Agreement between CMS Continental Natural Gas, Inc.
             and Pennaco Energy, Inc. dated March 1, 1999 (Portions of this Gas
             Gathering Agreement have been omitted based upon a request for
             confidential treatment. Additionally, the omitted portions have
             been filed with the SEC.) Filed as Exhibit 10.19 to the Company's
             Form SB-2 (Reg. No. 333-68317) and included herein by reference
    10.20    Gas Purchase Agreement between Western Gas Resources, Inc. and
             Pennaco Energy, Inc. dated April 1, 1999 (Portions of this Gas
             Purchase Agreement have been omitted based upon a request for
             confidential treatment. Additionally, the omitted portions have
             been filed with the SEC.) Filed as Exhibit 10.20 to the Company's
             Form SB-2 (Reg. No. 333-68317) and included herein by reference


                                      II-5




 Exhibit No. Title
 ----------- -----
          
    10.21    Base Contract for Short-Term Sale and Purchase of Natural Gas
             between Pennaco Energy, Inc. and Interenergy Resources Corporation
             dated April 1, 1999 (Portions of this Base Contract for Short-Term
             Sale and Purchase of Natural Gas have been omitted based upon a
             request for confidential treatment. Additionally, the omitted
             portions have been filed with the SEC.) Filed as Exhibit 10.21 to
             the Company's Form SB-2 (Reg. No. 333-68317) and included herein
             by reference
    10.22    Gas Sales and Purchase Agreement between Montana--Dakota Utilities
             Co. and Pennaco Energy, Inc. dated March 1, 1999 (Portions of this
             Gas Sales and Purchase Agreement have been omitted based upon a
             request for confidential treatment. Additionally, the omitted
             portions have been filed with the SEC. Filed as Exhibit 10.22 to
             the Company's Form SB-2 (Reg. No. 333-68317) and included herein
             by reference)
    10.23    Credit Facility (filed as Exhibit 4.1 to the Company's Form 10-QSB
             File No. 001-14943 for the quarter ended June 30, 1999, and
             included herein by reference).
   +23.1     Consent of KPMG LLP
   +23.2     Consent of Kummer Kaempfer Bonner & Renshaw (included in Exhibit
             5.1)
   +23.3     Consent of Ryder Scott Company

- --------
*Filed herewith.
**To be filed by amendment.
+Previously filed.

Item 17. Undertakings.

   Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant, the registrant has been advised that in the opinion of the
Securities and Exchange Commission such indemnification is against public
policy as expressed in the Act and is, therefore, unenforceable. In the event
that a claim for indemnification against such liabilities (other than the
payment by the registrant of expenses incurred or paid by a director, officer
or controlling person of the registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or
controlling person in connection with the securities being registered, the
registrant will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate jurisdiction
the question whether such indemnification by it is against public policy as
expressed in the Act and will be governed by the final adjudication of such
issue.

   The undersigned registrant hereby undertakes:

   (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement: (i) to include any
prospectus required by Section 10(a)(3) of the Securities Act of 1933; (ii) to
reflect in the prospectus any facts or events arising after the effective date
of the registration statement (or the most recent post-effective amendment
thereof) which, individually or in the aggregate, represent a fundamental
change in the information set forth in the registration statement.
Notwithstanding the foregoing, any increase or decrease in volume of securities
offered (if the total dollar value of securities offered would not exceed that
which was registered) and any deviation from the low or high end of the
estimated maximum offering range may be reflected in the form of prospectus
filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the
changes in volume and price represent no more than a 20% change in the maximum
aggregate offering price set forth in the "Calculation of Registration Fee"
table in the effective registration statement; and (iii) to include any
additional or changed material information on the plan of distribution.

   (2) that, for purposes of determining any liability under the Securities Act
of 1933, the information omitted from the form of prospectus filed as part of
this registration statement in reliance upon Rule 430A and contained in a form
of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or
497(h) under the Securities Act shall be deemed to be part of this registration
statement as of the time it was declared effective.

   (3) that, for the purpose of determining any liability under the Securities
Act of 1933, each post-effective amendment that contains a form of prospectus
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereto.

                                      II-6


                                   SIGNATURES

   Pursuant to the requirements of the Securities Act of 1933 the registrant
has duly caused this Amendment No. 2 to be signed on its behalf by the
undersigned, thereunto duly authorized, to the City of Denver, State of
Colorado, on the 11th day of October, 1999.

                                          Pennaco Energy, Inc.

                                                      /s/ Paul M. Rady
                                          By: _________________________________
                                                        Paul M. Rady
                                                  Chief Executive Officer,
                                               President, and Chairman of the
                                                           Board

   Pursuant to the requirements of the Securities Act of 1933, as amended, this
amendment has been signed by the following persons on October 11, 1999 in the
capacities indicated.



                  Name                                         Title
                  ----                                         -----

                                     
            /s/ Paul M. Rady            President, Chief Executive Officer, and
 ______________________________________  Chairman of the Board
              Paul M. Rady

        /s/ Glen C. Warren, Jr.         Chief Financial Officer, Executive Vice President,
 ______________________________________  and Director (Principal Financial and Accounting
          Glen C. Warren, Jr.            Officer)

         /s/ Gregory V. Gibson          Vice President, Legal, Secretary, and Director
 ______________________________________
           Gregory V. Gibson

                                        Director
 ______________________________________
             David W. Lanza


                                      II-7


                                 EXHIBIT INDEX



 Exhibit No. Title
 ----------- -----
          
    *1.1     Form of Underwriting Agreement
    +3.1     Amended and Restated Articles of Incorporation
     3.2     Bylaws (filed as Exhibit 3.2 to the Company's Form 10-SB, File No.
             00-24881, filed September 15, 1998 and included herein by
             reference)
     4.1     Form of Warrant (filed as Exhibit 4.1 to the Company's Form SB-2
             File No. 333-68317, filed December 3, 1998 and included herein by
             reference)
    +5.1     Opinion of Kummer Kaempfer Bonner & Renshaw
    10.1     Mineral Lease Purchase Agreement dated February 23, 1998 between
             High Plains Associates, Inc. and Pennaco Energy, Inc. (filed as
             Exhibit 10.1 to the Company's Form 10-SB/A File No. 00-24881,
             filed September 15, 1998 and included herein by reference)
    10.2     Letter Agreement dated January 23, 1998 between High Plains
             Associates, Inc. and Taylor Oil Properties (filed as Exhibit 10.2
             to the Company's Form 10-SB/A File No. 00-24881, filed September
             15, 1998 and included herein by reference)
    10.3     Assignment of Option and Exercise of Option dated March 6, 1998
             between High Plains Associates, Inc. and Pennaco Energy, Inc.
             (filed as Exhibit 10.3 to the Company's Form 10-SB/A File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.4     Agreement dated March 6, 1998 between High Plains Associates, Inc.
             and Pennaco Energy, Inc. (filed as Exhibit 10.4 to the Company's
             Form 10-SB/A File No. 00-24881, filed September 15, 1998 and
             included herein by reference)
    10.5     Pennaco Energy, Inc. 1998 Stock Option and Incentive Plan (filed
             as Exhibit 10.5 to the Company's Form 10-SB, File No. 00-24881,
             filed September 15, 1998 and included herein by reference)
    10.6     Form of Pennaco Energy, Inc. Incentive Stock Option Agreement
             (filed as Exhibit 10.6 to the Company's Form 10-SB, File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.7     Form of Pennaco Energy, Inc. Non-Statutory Stock Option Agreement
             (filed as Exhibit 10.7 to the Company's Form 10-SB, File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.8     Employment Agreement dated June 10, 1998 between Pennaco Energy,
             Inc. and Paul M. Rady (filed as Exhibit 10.8 to the Company's Form
             10-SB, File No. 00-24881, filed September 15, 1998 and included
             herein by reference)
    10.9     Employment Agreement dated July 2, 1998 between Pennaco Energy,
             Inc. and Glen C. Warren, Jr. (filed as Exhibit 10.9 to the
             Company's Form 10-SB, File No. 00-24881, filed September 15, 1998
             and included herein by reference)
    10.10    Secured Promissory Note dated August 13, 1998 from Pennaco Energy,
             Inc. to Venture Capital Sourcing, SA (filed as Exhibit 10.10 to
             the Company's Form 10-SB/A File No. 00-24881, filed September 15,
             1998 and included herein by reference)
    10.11    Second Amendment to Security Agreement dated August 13, 1998
             between Pennaco Energy, Inc. and Venture Capital Sourcing, SA
             (filed as Exhibit 10.11 to the Company's Form 10-SB/A File No. 00-
             24881, filed September 15, 1998 and included herein by reference)
    10.12    Purchase and Sale Agreement between Pennaco Energy, Inc., as
             Seller and CMS Oil and Gas Company, as Buyer, dated October 23,
             1998 (filed as Exhibit 10.12 to the Company's Form 10-SB, File No.
             00-24881, filed September 15, 1998 and included herein by
             reference)
    10.13    Secured Promissory Note dated October 23, 1998 from Pennaco
             Energy, Inc. to CMS Oil and Gas Company (filed as Exhibit 10.13 to
             the Company's Form 10-SB, File No. 00-24881, filed November 24,
             1998 and included herein by reference)
    10.14    Sublease Agreement dated October 23, 1998 between Pennaco Energy,
             Inc. and Evansgroup, Inc. (filed as Exhibit 10.14 to the Company's
             Form 10-SB/A File No. 00-24881 filed December 22, 1998 and
             included here by reference)





 Exhibit No. Title
 ----------- -----
          
    10.15    Agreement Regarding the Drilling of Coal Bed Methane Wells (filed
             as Exhibit 10.15 to the Company's Form 10-SB/A File No. 00-24881,
             filed December 22, 1998 and included herein by reference)
    10.16    First Amendment to Purchase and Sale Agreement dated November 20,
             1998 (filed as Exhibit 10.16 to the Company's Form 10-SB/A File
             No. 00-24881, filed January 28, 1999 and included herein by
             reference)
    10.17    Second Amendment to Purchase and Sale Agreement dated January 15,
             1999 (filed as Exhibit 10.17 to the Company's Form 10-SB/A File
             No. 00-24881, filed January 28, 1999 and included herein by
             reference)
    10.18    Gas Gathering Agreement between Bear Paw Energy, Inc. and Pennaco
             Energy, Inc. dated February 1, 1999 (Portions of this Gas
             Gathering Agreement have been omitted based upon a request for
             confidential treatment. Additionally, the omitted portions have
             been filed with the SEC. Filed as Exhibit 10.18 to the Company's
             Form SB-2 (Reg. No. 333-68317) and included herein by reference)
    10.19    Gas Gathering Agreement between CMS Continental Natural Gas, Inc.
             and Pennaco Energy, Inc. dated March 1, 1999 (Portions of this Gas
             Gathering Agreement have been omitted based upon a request for
             confidential treatment. Additionally, the omitted portions have
             been filed with the SEC. Filed as Exhibit 10.19 to the Company's
             Form SB-2 (Reg. No. 333-68317) and included herein by reference)
    10.20    Gas Purchase Agreement between Western Gas Resources, Inc. and
             Pennaco Energy, Inc. dated April 1, 1999 (Portions of this Gas
             Purchase Agreement have been omitted based upon a request for
             confidential treatment. Additionally, the omitted portions have
             been filed with the SEC. Filed as Exhibit 10.20 to the Company's
             Form SB-2 (Reg. No. 333-68317) and included herein by reference)
    10.21    Base Contract for Short-Term Sale and Purchase of Natural Gas
             between Pennaco Energy, Inc. and Interenergy Resources Corporation
             dated April 1, 1999 (Portions of this Base Contract for Short-Term
             Sale and Purchase of Natural Gas have been omitted based upon a
             request for confidential treatment. Additionally, the omitted
             portions have been filed with the SEC. Filed as Exhibit 10.21 to
             the Company's Form SB-2 (Reg. No. 333-68317) and included herein
             by reference)
    10.22    Gas Sales and Purchase Agreement between Montana-Dakota Utilities
             Co. and Pennaco Energy, Inc. dated March 1, 1999 (Portions of this
             Gas Sales and Purchase Agreement have been omitted based upon a
             request for confidential treatment. Additionally, the omitted
             portions have been filed with the SEC. Filed as Exhibit 10.22 to
             the Company's Form SB-2 (Reg. No. 333-68317) and included herein
             by reference)
    10.23    Credit Facility (filed as Exhibit 4.1 to the Company's Form 10-QSB
             File No. 001-14943 for the quarter ended June 30, 1999, and
             included herein by reference).
   +23.1     Consent of KPMG LLP
   +23.2     Consent of Kummer Kaempfer Bonner & Renshaw (included in Exhibit
             5.1)
   +23.3     Consent of Ryder Scott Company

- --------
*Filed herewith.
**To be filed by amendment.
+Previously filed.