CHEYENNE, Wyo. (AP) — Wyoming U.S. Sen. John Barrasso and Interior Secretary Sally Jewell are sparring over whether charging more for federal coal would kill the coal industry.

Jewell testified Tuesday before the Senate Energy and Natural Resources Committee on a three-year moratorium on federal coal leasing. The federal government will use the moratorium to study whether taxpayers are getting a fair return on federal coal.

Barrasso says demand for coal has collapsed. He asked Jewell whether higher federal royalties are a good idea because they could drive demand to zero.

Jewell says companies are paying a very low price for coal. She says criticism that taxpayers aren't getting a fair return on coal has been "very fair."

Close to 40 percent of the nation's coal production comes from federal reserves in Wyoming.