A truck moves coal at the Colowyo Mine about 30 miles south of Craig, Colo. on Wednesday, June 17, 2015. On the left is green reclaimed land that Colowyo has already mined. On the right is an active mining area.

(Nathaniel Minor/CPR News)

Coal production across Colorado hit a 23-year low last year, according to state data released this week from the Colorado Division of Mining and Safety. 

Colorado Mining Association President Stuart Sanderson says the state didn’t see any mine closures in 2015. But lower demand across the country has hit Colorado and other coal mining states hard.

“Of the top 15 states, every state had reductions in coal production," Sanderson said.

Coal production in Colorado fell 18 percent last year. Nationwide, it dropped 10 percent. 

“When you say demand, I think it’s important to say that demand is not the result of natural market forces. What we are seeing is lower demand engineered by government," Sanderson said.

Sanderson is referring to a 2010 law that prompted some utilities to retire coal fired power plants or convert them to natural gas. But some industry experts say the abundance of inexpensive natural gas is fueling the conversion of plants away from coal.