The Western Region (WR) performs an oversight role for States in the Region that have primacy and regulate surface coal mining activities and reclamation on lands within their jurisdiction. The WR has primacy for surface coal mining activities and reclamation that occur on Indian and Federal Lands in the west, as well as the state of Washington.

The WR Office, located in Denver, CO, has three divisions: Denver Field Division, Program Support Division, and Technology Management Division. Additionally, the Casper Area Office in Casper, Wyoming. The Regional Director coordinates and administers the day-to-day management, policy direction, and performance of the WR.