On that day, the 34-year-old plant near Beulah in Mercer County experienced a mechanical failure in one of its turbine-driven feedpumps. The entire plant tripped offline, with some tube lines rupturing, causing a fire. A piece of auxiliary equipment and the plant’s roof were damaged in the process. Coyote is a mine-mouth operation with Dakota Westmoreland Corp.’s Beulah lignite surface mine.

For about three weeks, the plant was completely out of service before repairs could be made to allow Coyote to resume about 50% capacity.

But repairs to the remainder of the plant would take considerably longer. In late December, the Fergus Falls, Minnesota-based utility was in the process of powering up Coyote after all of the repairs finally had been completed, according to company spokeswoman Cris Oehler.

Otter Tail operates Coyote and owns 35% of the baseload facility. Other co-owners include Northern Municipal Power Agency, 30%; Montana-Dakota Resources, 25%; and NorthWestern Energy, 10%.

Otter Tail remains primarily a coal-fired utility. In addition to Coyote, the company also owns the 475-megawatt Big Stone coal plant near Milbank, South Dakota, and the 138-megawatt Hoot Lake coal plant near Fergus Falls.

Hoot Lake currently is scheduled to run until 2021, when it will be retired and replaced in part by a new natural gas-burning plant. But Otter Tail has no plans to shutter Coyote and Big Stone or repower them with natural gas.

Dakota Westmoreland’s 9,000-acre Beulah mine, located about 75 miles northwest of Bismarck, North Dakota, annually produces about 3 million tons and has about 135 employees. The mine produced 1.65 million tons of coal in the first nine months of 2015, according to the Mine Safety and Health Administration.

Dakota Westmoreland officials have declined to comment on the impact of Coyote’s partial idling on the mine. It is a subsidiary of Westmoreland Coal Co. of Englewood, Colorado.