Exhibit 3.4

CERTIFICATE OF FORMATION

OF

SILVERTHORNE ENERGY HOLDINGS LLC

This Certificate of Formation of Silverthorne Energy Holdings LLC (the “Company”) dated September 8, 2010, has been duly executed and is filed pursuant to Section 18-201 of the Delaware Limited Liability Company Act (the “Act”) to form a limited liability company under the Act.

Article One

The name of the limited liability company formed hereby is “Silverthorne Energy Holdings LLC.”

Article Two

The address of the Company’s registered office in the State of Delaware is 1209 Orange Street, Wilmington, New Castle County, Delaware 19801.  The name the Company’s registered agent for service of process in the State of Delaware at such address is The Corporation Trust Company.

[Signature Page Follows]

IN WITNESS WHEREOF, the undersigned has executed this Certificate of Formation as of the date first written above.

AUTHORIZED PERSON
By:	/s/ H. Michael Krimbill
	Name:	H. Michael Krimbill
	Title:	Authorized Person