UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


                                 SCHEDULE 13D

                   Under the Securities Exchange Act of 1934


                                 T-REX OIL, INC.
             ------------------------------------------------------
                                (Name of Issuer)

                        Common Stock, $0.001 per share
             ------------------------------------------------------
                         (Title of Class of Securities)

                                   75188R106
              ------------------------------------------------------
                                (CUSIP Number)

                             Jon Clement Nicolaysen
                                 1134 S. Wolcott
                                Casper, WY 82601
                                 (720) 502-4483
             ------------------------------------------------------
                 (Name, Address and Telephone Number of Person
               Authorized to Receive Notices and Communications)

                               December 22, 2014
                 ---------------------------------------------
            (Date of Event which Requires Filing of this Statement)

If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  that is the subject of this  Schedule  13D, and is filing this
schedule because of ss.ss.240.13d-1(e),  240.13d-1(f) or 240.13d-1(g), check the
following box. /_/

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).


CUSIP No. 75188R106

1.   NAMES OF REPORTING PERSONS:

     Jon Clement Nicolaysen

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS):(a) /_/
                                                                         (b) /_/
3.   SEC USE ONLY:

4.   SOURCE OF FUNDS (SEE INSTRUCTIONS): N/A

5.   CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d)
     OR 2(e): /_/

6.   CITIZENSHIP OR PLACE OF ORGANIZATION:

     United States

                             7.  SOLE VOTING POWER:

                                 1,052,000 Common Shares
      NUMBER OF SHARES
      BENEFICIALLY OWNED     8.  SHARED VOTING POWER:
      BY EACH REPORTING
      PERSON WITH                0

                             9.  SOLE DISPOSITIVE POWER:

                                 1,052,000 Common Shares

                             10. SHARED DISPOSITIVE POWER:

                                 0

11.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:

     1,052,000  shares of Commons  Stock;  2,000  shares are owned  jointly with
     spouse

12.  CHECK IF THE  AGGREGATE  AMOUNT IN ROW (11)  EXCLUDES  CERTAIN  SHARES (SEE
     INSTRUCTIONS): /_/

13.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):

     6.67% Common Stock

14.  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):

     IN
----------------

                                      -1-


ITEM 1. SECURITY AND ISSUER
---------------------------

The security for which this report is made is the common stock, par value $0.001
per share, of T-Rex Oil, Inc., a Colorado corporation (the "Issuer").

ITEM 2. IDENTITY AND BACKGROUND.
--------------------------------

This  statement  on  Schedule  13D is  being  filed  on  behalf  of Jon  Clement
Nicolaysen, an individual. The mailing address of Mr. Nicolaysen is P.O. Box 40,
Henderson, CO 80640.

JON NICOLAYSEN, Age 68

Mr.  Nicolaysen  was  appointed  an  Executive  Vice  President of the Issuer in
December,  2014.  Prior to that,  he has  served  as the CEO and a  Director  of
Rancher Energy  Corporation  (kna T-Rex Oil, Inc.) since  September  2009. He is
also the  President  and a  director  of  Western  Interior  Oil & Gas Corp.  (a
subsidiary of Issuer).

Mr.  Nicolaysen  through his  company,  JK Minerals  Inc.,  was a  non-operating
working interest owner, but by 1997 he had bought out the other working interest
owners and as Operator,  began a successful 2nd Frontier  development program at
Cole Creek in Wyoming.

In 2005, Slawson Exploration Inc. took over as operator and continued to develop
the Frontier and Dakota formations.  Eventually,  Blue Tip Inc. purchased all of
Slawson's and JK's  interests in the Frontier and Dakota.  In 2006, he purchased
the majority working interest in the Shannon  formation at Cole Creek through JK
Minerals  Inc. In 2004,  he was part of a group that  redeveloped  the Big Muddy
Field in Converse  County,  Wyoming.  In 2007, these fields were sold to Rancher
Energy (kna T-Rex Oil, Inc.) for $25 million.

In 2009,  as a  dissatisfied  shareholder,  he led a successful  proxy fight for
control of Rancher Energy (kna T-Rex Oil, Inc.) He led the Company  successfully
through a Chapter 11 bankruptcy process paying off all creditors in full.

Mr. Nicolaysen provides the board of directors with not only his experience with
a public reporting company but also his experience in the oil and gas industry.

Mr. Nicolaysen has not, during the last five years, been convicted in a criminal
proceeding (excluding traffic violations or similar misdemeanors).

Mr.  Nicolaysen  has not,  during the last five  years,  been a party to a civil
proceeding of a judicial or administrative body of competent jurisdiction and as
a result of such  proceeding  was or is subject to a  judgment,  decree or final
order  enjoining  future  violations of, or prohibiting or mandating  activities
subject  to,  federal or state  securities  laws or finding any  violation  with
respect to such laws.

Mr. Nicolaysen is a citizen of the United States of America.


ITEM 3. SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION
---------------------------------------------------------

In August  2014,  Mr.  Nicolaysen,  an officer and  director of Terex was issued
750,000  shares of the common stock of Terex Energy  Corp.  for services  with a
value of $750,000.  In addition in August 2014, Mr. Nicolaysen purchased 300,000
shares of common  stock of T-Rex at a price of $1.00 per share.  On December 22,
2014,  T-Rex Oil, Inc.  acquired 100% of the  outstanding  stock of Terex Energy
Corp. after exchanging 7,385,700 shares with Terex Energy Corp.  shareholders on
a one for one basis.



                                      -2-


ITEM 4. PURPOSE OF TRANSACTION
------------------------------

Mr.  Nicolaysen is sole owner of the 1,050,000  shares of the Issuer and as such
has the ability to vote the shares.  He jointly owns 2,000 shares with his wife.
In addition,  Mr. Nicolaysen is a Director and Executive Vice President of T-Rex
Oil and  President  and a  Director  of  Western  Interior  Oil & Gas  Corp.  (a
subsidiary of Issuer),  and as such Mr.  Nicolaysen  may influence the following
which relate to, or could result in the matters  referred to in  paragraphs  (a)
through  (j),  inclusive,  of the  instructions  to  Item 4 of  Schedule  13D as
follows:  a) acquisitions  of prospects which continue for Issuer,  based on the
business  judgment of the continuing  board of directors b) the reporting person
intends to formulate a plan to recapitalize the Issuer for at least $10,000,000,
(although  there can be no assurance that the Issuer will  successfully  achieve
that, or any,  additional debt or equity  capitalization)  d)  authorization  of
preferred stock will require amendments to the Articles of Incorporation.

The  Reporting  Person  may,  at any  time  and from  time to  time,  review  or
reconsider  their position  and/or change his purpose and/or  formulate plans or
proposals with respect thereto.


ITEM 5. INTEREST IN SECURITIES OF THE ISSUER
--------------------------------------------

The  percentages of outstanding  shares of T-Rex Oil, Inc. common stock reported
below are based on the statement that as of July 15, 2015, there were 15,771,142
shares of T-Rex Oil, Inc. common stock outstanding.

     (a) Mr.  Nicolaysen  beneficially owns or may be deemed to beneficially own
shares of T-Rex Oil, Inc. common stock as follows:

                                    No. of Shares            % of Class
                                    -----------------        -------------
         Common Shares              1,052,000                 6.67%

     (b) For  information  regarding  the  number of shares of T-Rex  Oil,  Inc.
common  stock as to which  Mr.  Nicolaysen  holds or  shares or may be deemed to
hold, reference is made to items (7) - (12) of the cover page for this statement
on Schedule 13D.

     (c) Other  than as set forth  herein,  there have been no  transactions  in
shares of T-Rex Oil, Inc.  common stock  effected by Mr.  Nicolaysen  during the
past 60 days.

     (d) No other  person  has the right to  receive  or the power to direct the
receipt of dividends from, or the proceeds from the sale of, such securities.

     (e) The date on which the  reporting  person  ceased to be the  beneficiary
owner of more than five percent of the class of securities: Not applicable

ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO
SECURITIES OF THE ISSUER.
--------------------------------------------------------------------------------

Mr. Nicolaysen has an employment agreement, dated November 2014 with the Issuer.

Mr. Nicolaysen also has a Farmout Agreement, dated June 25, 2015, by and between
Terex Energy Corp.  (a wholly owned  subsidiary  of the Issuer) and Red Hawk Oil
Exploration, Inc., an entity he is and officer and director and shareholder of.

Mr.  Nicolaysen  has  no  other  contracts,   arrangements,   understandings  or
relationships  (legal or  otherwise)  with  other  persons  with  respect to the
securities  of T-Rex Oil,  Inc.,  other than as described  in this  statement on
Schedule 13D.

                                      -3-



ITEM 7. MATERIAL TO BE FILED AS EXHIBITS.
-----------------------------------------

Not Applicable




                                   SIGNATURES

After  reasonable  inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.


                                       Date: July 31, 2015



                                       /s/ Jon Clement Nicolaysen
                                       ---------------------------------
                                       Jon Clement Nicolaysen, Individual



































                                      -4-