EXHIBIT 10.6

                      ASSIGNMENT OF OIL AND GAS LEASE WITH
                        RESERVATION OF OVERRIDING ROYALTY

          Know All Men by These Presents,  that the  undersigned,  Nova Leasing,
LLC., hereinafter called Assignor (whether one or more) for and in consideration
of Sixty-Four Thousand Dollars, the receipt whereof is hereby acknowledged, does
hereby  sell,  assign,  transfer  and  set  over  to  Sun  River  Energy,  Inc.,
hereinafter called Assignee,  all of its right,  title and interest,  subject to
the overriding  royalty  reservation  hereinafter set out, in and to the oil and
gas lease  dated  August 2, 2004 , from the State of  Wyoming,  lessor,  to Nova
Leasing,  LLC.,  lessee,  recorded as WY-04-00375 , insofar as said lease covers
the following described land in Natrona County, State of Wyoming: Sec 16, T 37N,
R 77W and containing 640 acres, more or less,  together with the rights incident
thereto and the  personal  property  thereon,  appurtenant  thereto,  or used or
obtained in connection therewith.

          The Assignor herein expressly  excepts,  reserves and retains title to
an  undivided  3.5% of all oil,  gas and  casinghead  gas  produced,  saved  and
marketed  from the above  described  land under the  provisions of the aforesaid
lease, or any extension or renewal thereof, as an overriding  royalty,  free and
clear  of any  cost  and  expense  of the  development  and  operation  thereof,
excepting taxes applicable to said interest and the production therefrom.  There
is an existing 12.5% royalty to the State of Wyoming, and an existing 4% royalty
to Sharon Fowler as contained in the previous  assignment  from Sharon K. Fowler
to Assignor.

          This Assignment is conditional upon Assignees agreement.  To begin the
drilling  of a well on some part of the above  described  land  within  270 days
hereafter  subject  to  drilling  rig.  availability  for which this date may be
extended,  and continue such drilling with reasonable diligence until a well has
been completed to the known oil producing sand of that territory,  or granite or
other impenetrable substances, through which a reasonably prudent operator would
not undertake to drill,  be  encountered.  If such well is not commenced by such
date, or extension  thereof,  then this Assignment  shall be terminated and will
expire.

          And for  the  same  consideration  the  Assignor  covenants  with  the
Assignee,  its or his heirs,  successors  or assigns,  that the  Assignor is the
lawful owner of and has good title to the interest above assigned in and to said
lease, estate, rights and property, free and clear from all liens,  encumbrances
or adverse claims;  that said lease is a valid and subsisting  lease on the land
above described, and all rentals and royalties due thereunder have been paid and
all  conditions  necessary  to keep  the  same  in full  force  have  been  duly
performed;  and that the  Assignor  will  warrant  and  forever  defend the same
against all persons whomsoever, lawfully claiming or to claim the same.

     Executed this 17th day of April, 2006.

ASSIGNEE                                                      ASSIGNOR
Sun River Energy, Inc.                                       Nova Leasing, LLC

By: Michael A. Littman, President                           By: Robert G. Fowler






STATE OF COLORADO

COUNTY OF JEFFERSON

          On this 17th day of April 2006,  before me, the undersigned,  a Notary
Public in and for said State, personally appeared Robert Fowler, Manager of Nova
Leasing,  LLC,  known to me to be the person  whose name is  subscribed  to this
within instrument, and who upon oath swore that the statements therein contained
are true and correct.

WITNESS my hand and official seal.

My Commission expires: 3/20/2010
                       ---------


                                  Notary Public
                                Cynthia Shoemaker



STATE OF COLORADO
COUNTY OF JEFFERSON                                           ss.

          On this 17th day of April 2006,  before me, the undersigned,  a Notary
Public in and for said State, personally appeared Michael A. Littman,  President
of Sun River Energy, Inc., known to me to be the person whose name is subscribed
to this within  instrument,  and who upon oath swore that the statements therein
contained are true and correct.

WITNESS my hand and official seal.

My Commission expires: 3/20/2010

                                  Notary Public
                                Cynthia Shoemaker