DGS was lead counsel for Marathon Oil Company in Park County Res. Council v. U.S. Dept. of Agriculture, 817 F.2d 609 (10th Cir. 1987), a landmark Tenth Circuit Court of Appeals interpreting the scope of NEPA documentation required prior to federal oil and gas lease issuance.  The Tenth Circuit established the NEPA principle that federal land management agencies are not required to prepare a comprehensive environmental impact statement prior to issuing federal oil and gas leases.