At the most recent Wyoming federal lease sale, held by the Bureau of Land Management in April, the two parcels that fetched the highest bids were both in the Wind River Basin. Kerr-McGee Corp., based in Oklahoma City, bid $310 per acre for one 1,111-acre parcel in 37n-90w and $305 per acre for another 160-acre tract, in 39n-93w. Both blocks lie just outside of producing units. Kerr-McGee has been building its presence in the western U.S. since its acquisition of HS Resources, a Denver-based independent, in August 2001. Between January 2002 and April 2003, 56,000 acres of federal leases were taken in the Wind River, for an average price per acre of $23.98, says Mark Chase, a partner with Englewood, Colorado-based Premier Data Services. Presently, there are 1,870 active federal leases in the area between 31n-40n and 80w-94w, comprising 1.35 million acres. The federal government is the dominant landowner in this part of Wind River Basin, which has only limited fee lands. Of the currently active federal leases, 612 are due to expire between now and the end of 2005. In the next two Wyoming federal land sales, scheduled for July and August, 67 parcels containing 68,000 acres are coming up for bid in the Wind River Basin. "During the next two and a half years, a lot of acreage will become available in the basin," says Chase. "Companies will need to drill that acreage or it will expire." Active operators in the Wind River include Yates Petroleum, Westport Resources, Burlington Resources, Tom Brown, Bill Barrett Corp. and Samson Investment Co.