The Bureau of Land Management has launched a 30-day public comment period on a proposed oil and gas lease sale in December involving more than 50,000 acres in northwest Colorado, including acreage outside Collbran and in Garfield County north of Mack.

The agency is proposing offering 61 parcels totaling 51,068 acres in the sale. A modified proposal would drop an 80-acre Jackson County parcel from the sale pending further analysis of unresolved conflicts over whether it should be made available to be leased, the BLM says.

Much of the acreage proposed to be offered is in far-northwest Colorado. A 722-acre parcel lies just under 3 miles southeast of Collbran and 3 miles west of Vega State Park, on a mix of private and BLM-managed federal land.

Two adjacent, square-mile parcels lie nearly 20 miles north of Mack. Another 40-acre parcel is nearby them, also in Garfield County.

The Garfield County and Collbran-area parcels all are in areas that have seen oil and gas development. Some of the Garfield acreage also is 1.6 miles northeast of the Demaree Canyon Wilderness Study Area.

According to a hypothetical development scenario contained in a draft environmental analysis, the 1,320 acres in Garfield County could see a total of six directionally drilled wells drilled from two, 3-acre well pads, with the wells reaching out laterally as far as two miles underground. The Collbran-area acreage could see 64 wells drilled from a total of four, 7-acre pads.

Fifty-six comments on the lease sale proposal were submitted during a public scoping period and were considered in development of the environmental assessment.

“Scoping comments expressed concerns related to air resources, aquatic species, conservation easements, lands with wilderness characteristics, local regulations, plant species, policy and procedure, recreation, socioeconomics, water resources, wild horses, and wildlife, including big game and Greater sage-grouse,” according to that document.

All but five parcels overlap big game or greater sage-grouse habitat. The BLM says it is applying lease stipulations from its management plans for greater sage-grouse and for big game habitat in Colorado.

Maps, the draft environmental assessment and other information, including on how to comment on the proposed lease sale, may be found at https://eplanning.blm.gov/eplanning-ui/project/2036196/510.

The comment period ends July 18.

The BLM also is proposing a lease sale in September that involves more than 12,000 acres, most of that lying northwest of Meeker.