Document:

Filed by sedaredgar.com - Yellowcake Mining, Inc. - Exhibit 10.20

RELINQUISHMENT and SURRENDER of LEASE and OPTION 

Yellowcake Mining, Inc. (the “Lessee”), pursuant to a
certain lease and option agreement made between the Lessee and Bedrock
Development Corp. (the “Lessor”) dated December 28, 2007 (the “Lease and
Option”), hereby terminates and cancels said Lease and Option effective
immediately and all rights and obligations under said Lease and Option are
hereby cancelled. 

All the interests of Lessee in the property
under or by virtue of the Lease and Option are hereby absolutely extinguished
effective immediately. 

The Lessee hereby quits claims to the real property more
particularly described in Schedule “A” attached hereto, together with all
appurtenances and water rights incident thereto.

This agreement shall be binding upon the parties, their
successors, assigns and personal representatives. 

In witness whereof, the Lessee has signed this 15th day of May,
2009. 

YELLOWCAKE MINING INC. 

	By: 	/s/ William Tafuri 
	Name: 	William Tafuri 
	Title: 	President, CFO, Secretary and
      Treasurer 

	PROVINCE OF BRITISH COLUMBIA 	) 
	  	)SS 
	COUNTY OF ____________________	) 

On this 15th day of May, 2009, there personally came before me
William Tafuri, as President and CEO of Yellowcake Mining, Inc., a Nevada
corporation and acknowledged the foregoing to be his free act and deed in his
said capacity and the free act and deed of said a Nevada corporation. 

/s/ Karen Richardson 

NOTARY PUBLIC 

	 	Residing at: 	KAREN F. RICHARDSON 
	 	  	Barrister & Solicitor 
	 	  	800-885 West Georgia Street 
	 	  	Vancouver, BC V6C 3H1 
	 	  	Telephone: (604) 687-5700 

My Commission Expires: 

My commission never expires 

- 2 - 

Schedule “A”

Mining Properties and Disclosure of Matters Relating to
Mining Properties 

Unpatented lode mining claims known as the Return Mine Claim
Group 

Legal Description: 

	
CLAIM GROUPS AND 
CLAIM NAMES 	
LOCATION 
DATE 	

CMC NO. 	DATE 
FILED 
WITH
      BLM 	
CO. DOC. 
NO. 	

DATE REC. 	

LOCATOR 
	  	  	  	  	  	  	  
	Carpenter
      Group 	  	  	  	  	  	  
	  	  	  	  	  	  	  
	
Carpenter 	
2-5-2005 	
254213 	
5-5-2005 	
733042 	
2-16-2005 	Ron E. Beck & 
Bruce L. Beck 
	Rocker 	"
	254214 	"
	733048 	"
	"
  
	Easy Street 	"
	254215 	"
	733047 	"
	"
  
	Redemption 	"
	254216 	"
	733046 	"
	"
  
	Exceptional 	"
	254217 	"
	733045 	"
	"
  
	Soldier 	"
	254218 	"
	733044 	"
	"
  
	Excavator 	"
	254219 	"
	733043 	"
	"
  
	Return 	"
	254220 	"
	733041 	"
	"
  
	  	  	  	  	  	  	  
	Little
      Debbie Group 	  	  	  	  	  	  
	  	  	  	  	  	  	  
	
Little Debbie
    	
4-16-2005 	
254682 	
7-12-2005 	
737171 	
5-9-2005 	Ron E. Beck & 
Bruce L. Beck 
	Monster 	"
	254683 	"
	737172 	"
	"
  
	Wendy 	"
	254684 	"
	737173 	"
	"
  
	Amos 	"
	254685 	"
	737174 	"
	"
  
	Crom 	"
	254686 	"
	737175 	"
	"
  
	Auntie 	"
	254687 	"
	737176 	"
	"
  
	Pappy 	"
	254688 	"
	737177 	"
	"
  
	Mammy 	"
	254689 	"
	737178 	"
	"
  
	Betty Jean 	"
	254690 	"
	737179 	"
	"
  
	MJB 	"
	254691 	"
	737180 	"
	"
  
	Zack 	"
	254692 	"
	737181 	"
	"
  
	Hope 	"
	254693 	"
	737182 	"
	"
  
	Past Time
      Group 	  	  	  	  	  	  
	  	  	  	  	  	  	  
	
Past Time 	
10-14-2005 	
256647 	
1-11-2006 	
746763 	
11-16-2005 	Ron E. Beck & 
Bruce L. Beck 
	Gary Lyn 	"
	256648 	"
	746765 	"
	"
  
	North Star 	"
	256649 	"
	746764 	"
	"
  
	Jack 	"
	256650 	"
	746761 	"
	"
  
	Rachual 	"
	256651 	"
	746760 	"
	"
  

Disclosure of Matters Relating to Mining
Properties 

Lessor’s title to the Mining Properties is expressly subject to
the following defects, encroachments, impairments or overlaps of the Mining
Properties, upon rights of others. 

- 3 - 

	 	1. 	
      Overlaps of any portion of any Mining Properties upon
      State Lands where the State of Colorado has the mineral interest, or upon
      federal lands withdrawn from mineral entry.

	 	2. 	
      Surface rights grantees, licensees and permittees of the
      United States and State of Colorado, including, but not limited to grazing
      rights (permits or leases), rights of ways, roads, utility corridors, and
      water rights recognized by the Colorado State Engineer or reserved to the
      Federal Government

	 	3. 	
      Rights of parties to non-locatable minerals, including
      but not limited to oil, gas, coal, hydrocarbons, leaseable minerals,
      leaseable resources, and common minerals

	 	4. 	
      Overlaps of any claims constituting the Mining
      Properties, where the claim is in itself otherwise valid except to the
      extent of its overlaps upon (1) other mining claims having a valid
      priority of the area of the overlap, (2) patented mineral estates, (3)
      State Lands or (4) federal lands not open to mineral entry such as the
      lands in Atomic Energy Withdrawal areas.

	 	5. 	
      Any defect in title resulting from the late payment or
      non-payment of initial or annual filing and maintenance fees, where the
      claims affected have relocated and have been or will be timely filed with
      the Bureau of Land Management.

	 	6. 	
      Defects resulting from the location of claims within
      Power Site Classifications where such claims have been relocated and have
      been or will be timely filed with the Bureau of Land
  Management.Filed by sedaredgar.com - Yellowcake Mining, Inc. - Exhibit 10.21

RELINQUISHMENT and SURRENDER of LEASE and OPTION 

FOR GOOD AND VALUABLE CONSIDERATION, the receipt and
sufficiency of which being hereby acknowledged, Yellowcake Mining, Inc.
(the “Lessee”), and Eagle Venture Group LLC (the “Lessor”), under a
certain lease and option agreement made between the parties dated December 28,
2007 (the “Lease and Option”), do hereby mutually agree to terminate and cancel
said Lease and Option effective immediately and all rights and obligations under
said Lease and Option are hereby cancelled. 

All the interests of Lessee in the property
under or by virtue of the Lease and Option are hereby absolutely extinguished
effective immediately. The Lessee hereby releases the
Lessor from all obligations arising under the Lease and Option. The Lessor
hereby releases the Lessee from all obligations arising under the Lease and
Option. 

The Lessee hereby quits claims to the real property more
particularly described in Schedule “A” attached hereto, together with all
appurtenances and water rights incident thereto.

This agreement shall be binding upon the parties, their
successors, assigns and personal representatives. 

In witness whereof, the Lessee has signed this 15th day of May,
2009. 

YELLOWCAKE MINING INC. 

	By: 	/s/ William Tafuri 
	Name: 	William Tafuri 
	Title: 	President, CFO, Secretary and
      Treasurer 

	PROVINCE OF BRITISH COLUMBIA 	) 
	  	)SS 
	COUNTY OF ____________________	) 

On this 15th day of May, 2009, there personally came before me
William Tafuri, as President and CEO of Yellowcake Mining, Inc., a Nevada
corporation and acknowledged the foregoing to be his free act and deed in his
said capacity and the free act and deed of said a Nevada corporation. 

/s/ Karen Richardson 

NOTARY PUBLIC 

	 	Residing at: 	KAREN F. RICHARDSON 
	 	  	Barrister & Solicitor 
	 	  	800-885 West Georgia Street 
	 	  	Vancouver, BC V6C 3H1 
	 	  	Telephone: (604) 687-5700 

My Commission Expires: 

My commission never expires 

- 2 - 

Schedule “A” 

Mining Properties and Disclosure of Matters Relating to
Mining Properties 

The Switchback Claims 

Legal Description: 

	

CLAIM GROUPS AND 
CLAIM NAMES
	

LOCATION
DATE 	

CMC NO. 	DATE
      
FILED 
WITH 
BLM 	

CO. DOC.
      
NO. 	

DATE REC.
	

LOCATOR 	

        

        COMMENTS
    
	  	  	  	  	  	  	  	  
	Switchback #1A Group 	 
    	 
    	 
    	 
    	 
    	 
    	 
    
	  	  	  	  	  	  	  	  
	

Swithback #1A 	

12-10-2005* 	

256652 	

1-13-2006 	

748478 	

12-21-2005 	Eagle 
Venture 
Group LLC 	
*Amendment 
Date 
	Swithback #2A 	"
	256653 	"
	748479 	"
	"
	"
  
	Swithback #3A 	"
	256654 	"
	748480 	"
	"
	"
  
	Swithback #4A 	"
	256655 	"
	748481 	"
	"
	"
  
	Swithback #5A 	"
	256656 	"
	748482 	"
	"
	"
  
	Swithback #6A 	"
	256657 	"
	748483 	"
	"
	"
  
	Swithback #7A 	"
	256658 	"
	748484 	"
	"
	"
  
	Switchback #10A 	"
	256659 	"
	748485 	"
	"
	"
  
	Switchback #11A 	"
	256660 	"
	748486 	"
	"
	"
  
	Switchback #12A 	"
	256661 	"
	748487 	"
	"
	"
  
	Switchback #13A 	"
	256662 	"
	748488 	"
	"
	"
  
	Switchback #14A 	"
	256663 	"
	748489 	"
	"
	"
  
	Switchback #15A 	"
	256664 	"
	748490 	"
	"
	"
  
	Switchback #16A 	"
	256665 	"
	748491 	"
	"
	"
  
	Switchback #17A 	"
	256666 	"
	748492 	"
	"
	"
  
	Switchback #18A 	"
	256667 	"
	748493 	"
	"
	"
  
	Switchback #19 	11-23-2005 	256668 	"
	748466 	"
	"
	 
    
	Switchback #20 	"
	256669 	"
	748467 	"
	"
	 
    
	Switchback #21 	"
	256670 	"
	748468 	"
	"
	 
    
	Switchback #22 	"
	256671 	"
	748469 	"
	"
	 
    
	Switchback #23 	"
	256672 	"
	748470 	"
	"
	 
    
	Switchback #24 	"
	256673 	"
	748471 	"
	"
	 
    
	Switchback #25 	"
	256674 	"
	748472 	"
	"
	 
    
	Switchback #26 	11-23-2005 	256675 	"
	748473 	"
	"
	 
    
	Switchback #27 	"
	256676 	"
	748474 	"
	"
	 
    
	Switchback #28 	"
	256677 	"
	748475 	"
	"
	 
    
	Switchback #29 	"
	256678 	"
	748476 	"
	"
	 
    
	Switchback #30 	"
	256679 	"
	748477 	"
	"
	 
    

- 3 - 

	The Last Dollar Group 	  	  	  	  	  	  	 
	  	  	  	  	  	  	  	 
	

The Last Dollar #1 	

11-25-2005 	

257734 	

2-23-2006 	

748620 	

12-23-2005 	Eagle 
Venture 
Group LLC 	

	The
      Last Dollar #2 	"
	257735 	"
	748621 	"
	"
	 
	The
      Last Dollar #3 	"
	257736 	"
	748622 	"
	"
	 
	The
      Last Dollar #4 	"
	257737 	"
	748623 	"
	"
	 
	The
      Last Dollar #5 	"
	257738 	"
	748624 	"
	"
	 
	The
      Last Dollar #6 	"
	257739 	"
	748625 	"
	"
	 
	The
      Last Dollar #7 	"
	257740 	"
	748626 	"
	"
	 
	The
      Last Dollar #8 	11-26-2005 	257741 	"
	748627 	"
	"
	 
	The
      Last Dollar #9 	"
	257742 	  	748628 	"
	"
	 
	The
      Last Dollar #10 	"
	257743 	"
	748629 	"
	"
	 
	The
      Last Dollar #11 	"
	257744 	"
	748630 	"
	"
	 
	  	  	  	  	  	  	  	 
	  	  	  	  	  	  	  	 
	Switchback #8 Group 	  	  	  	  	  	  	 
	  	  	  	  	  	  	  	 
	

Switchback #8 	

1-1-2006 	

257923 	

3-30-2006 	

749899 	

1-24-2006 	Eagle 
Venture 
Group LLC 	

	Switchback #9 	"
	257924 	"
	749900 	"
	"
	 
	Switchback #31 	1-3-2006 	257925 	"
	750104 	1-30-2006 	"
	 
	Switchback #32 	"
	257926 	"
	750105 	"
	"
	 
	Switchback #33 	"
	257927 	"
	750106 	"
	"
	 
	  	  	  	  	  	  	  	 
	Switchback #2AB Group 	  	  	  	  	  	  	 
	  	  	  	  	  	  	  	 
	

Switchback #2AB 	

3-30-2007 	

268804 	

6-22-2007 	

771941 	

4-25-2007 	Eagle 
Venture 
Group LLC 	

	Switchback #3AB 	"
	268805 	"
	771942 	"
	"
	 
	Switchback #4AB 	"
	268806 	"
	771943 	"
	"
	 
	Switchback #5AB 	"
	268807 	"
	771944 	"
	"
	 
	Switchback #15AB 	"
	268808 	"
	771945 	"
	"
	 
	Switchback #16AB 	"
	268809 	"
	771946 	"
	"
	 
	Switchback #17AB 	"
	268810 	"
	771947 	"
	"
	 
	Switchback #20AB 	"
	268811 	"
	771948 	"
	"
	 
	Switchback #28AB 	"
	268812 	"
	771949 	"
	"
	 
	

Switchback #31AB 	

" 	

268813 	

" 	

771950 	

" 	Eagle 
Venture 
Group LLC 	

	Switchback #32AB 	"
	268814 	"
	771951 	"
	"
	 

- 4 - 

Disclosure of Matters Relating to Mining Properties

Lessor’s title to the Mining Properties is expressly subject to
the following defects, encroachments, impairments or overlaps of the Mining
Properties, upon rights of others. 

	 	1. 	
      Overlaps of any portion of any Mining Properties upon
      State Lands where the State of Colorado has the mineral interest, or upon
      federal lands withdrawn from mineral entry.

	 	2. 	
      Surface rights grantees, licensees and permittees of the
      United States and State of Colorado, including, but not limited to grazing
      rights (permits or leases), rights of ways, roads, utility corridors, and
      water rights recognized by the Colorado State Engineer or reserved to the
      Federal Government

	 	3. 	
      Rights of parties to non-locatable minerals, including
      but not limited to oil, gas, coal, hydrocarbons, leaseable minerals,
      leaseable resources, and common minerals

	 	4. 	
      Overlaps of any claims constituting the Mining
      Properties, where the claim is in itself otherwise valid except to the
      extent of its overlaps upon (1) other mining claims having a valid
      priority of the area of the overlap, (2) patented mineral estates, (3)
      State Lands or (4) federal lands not open to mineral entry such as the
      lands in Atomic Energy Withdrawal areas.

	 	5. 	
      Defects resulting from the location of claims within
      Power Site Classifications where such claims have been relocated and have
      been or will be timely filed with the Bureau of Land Management.

	 	6. 	
      Any defect in title resulting from the late payment or
      non-payment of initial or annual filing and maintenance fees, where the
      claims affected have relocated and have been or will be timely filed with
      the Bureau of Land Management.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00159-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00159-of-00352.parquet"}]]