DOUGLAS n Antelope Coal Mine is asking the Bureau of Land Management to put out to bid a lease to mine about 465 million tons of federal coal.

The BLM has issued a draft environmental impact statement evaluating the impacts of mining the two Powder River Basin tracts. The document estimates that, if Antelope Coal is the successful lease bidder, the tracts could extend mine life by up to 13 years and add up to 40 new jobs.

The lease could also prove valuable to government coffers by keeping some mining activity in Converse County.

However, the BLM environmental analysis is only the first step toward allowing the federal coal to be mined. If the analysis is approved, the agency would then take sealed bids on the lease. The successful bidder would have to obtain a mining permit from the state Department of Environmental Quality.

In the draft environmental impact statement, the agency proposes an alternative that would add about 2200 acres to the tracts sought by Antelope Coal. The additional coal, estimated at 65 million tons, could end up isolated if it is not incorporated into the current lease, said Mike Karbs, BLM assistant field manager for the Casper office.

"We added it primarily to make sure no coal is bypassed, or left in an unminable condition," he said. He added that the agency won't declare a preferred alternative until public comments have been received on the draft statement.

Heidi Lowe, community relations manager for Rio Tinto Energy America, Antelope's parent company, said the mine is preparing comments on the draft EIS to issue at a later date.

Located at the southern tip of the coal-rich Powder River Basin, Antelope Coal Company is the only mine with operations in Converse County. Those activities make the company the county's largest taxpayer, generating about $9.4 million in ad valorum taxes annually, county treasurer Joel Schell said. That's about six times more than the second-highest taxpayer added to county coffers in 2007.

Converse County Commission Chairman Jim Willox said the lease would add value to the county's economy through taxes and new jobs. His lingering concern is how the BLM may address impacts from coal dust on air quality and fire fighting services.

Although only one mine operates in Converse County, a majority of the coal mined in the entire Powder River Basin is exported on rail lines through the county, Willox explained. Coal dust accumulates in piles in some places along the tracks, creating fire hazards that are difficult and expensive to deal with.

Karbs said the agency is trying to address the coal dust issues, but so far hasn't been able to identify a single responsible party.

Antelope Coal petitioned the BLM to lease the tracts not long before a slew of applications hit the agency. Those other applications have been grouped together under three environmental impact statement analyses. One will evaluate the potential impacts from four leases between Wright and Gillette. Another involves six applications south of Wright. And, the BLM is working on an EIS for a single lease north of Gillette, Karbs said.