GILLETTE, Wyo. (AP) — Mines in Campbell County produced slightly less coal in 2011 than in 2010.

According to figures released by the federal government, Campbell County mines produced 426.4 million short tons of coal last year. In 2010, they produced 428.3 million short tons of coal.

The North Antelope Rochelle mine owned by Peabody Energy Corp. produced the most coal at about 109 million tons.

The Gillette News-Record reports ( ) that the Mining Safety and Health Administration's data is preliminary.

Overall production has not returned to 2008 levels, when a record 451.7 short tons was produced.

There are 12 coal mines in Campbell County, which is part of the Powder River Basin. But most of the basin coal is produced in Campbell County.