BILLINGS, Mont. (AP) — Experts will discuss hard times in the coal industry at a conference in Montana.

The Powder River Basin of Wyoming and Montana is the top coal-producing region in the U.S. The basin provides about 40 percent of the nation's coal.

Competition from inexpensive natural gas and renewable energy means hardship for the area's mines. Tighter pollution regulations are also causing utilities to stop burning coal to make electricity.

Fourteen experts from diverse backgrounds will discuss those and other issues in Billings on Friday.

Other attendees include former New Mexico Gov. Bill Richardson, a former U.S. energy secretary who will discuss energy production in the West.