BISMARCK, N.D. (AP) _ State and federal agencies are working to extinguish underground coal fires in Slope and McKenzie Counties.
Officials say the subterranean fire in Slope County has been burning since 2008, and the fire in McKenzie County has been burning since 1999.
Coal bed fires are usually related to prairie fires.
Officials say a $27,000 grant is being used to battle the below-ground blazes. They say the plan is to use earthmoving equipment to dig across burning coal seams, and backfill the trenches with dirt.
Geologists say explorers Meriwether Lewis and William Clark noted underground coal fires during a visit to North Dakota two centuries ago.