GILLETTE, Wyo. (AP) — Black Hills Corp. has laid off 11 of its workers at the Wyodak coal mine north of Gillette.

Black Hills external affairs manager Wes Ashton tells the Associated Press the layoffs are in response to changing market conditions.

The layoffs leave the surface coal mine with 69 employees.

The Wyodak mine was expected to produce 4.5 million tons of coal this year after producing 5.6 million tons last year.

Production at the mine has been 3.1 million tons so far this year.