DENVER (February 25, 2009) - Arch Coal, Inc. (NYSE:ACI) announced that Mountain Coal Company's West Elk mine employees were honored today with two Colorado state environmental awards at the 111th National Western Mining Conference and Exhibition in Denver.

The Colorado Division of Reclamation Mining and Safety recognized West Elk mine for the proactive reconstruction of Monument Dam. The Colorado Department of Public Health and Environment in cooperation with the Colorado Mining Association presented West Elk with Colorado's Pollution Prevention Award for its proactive conservation and recycling measures.

According to the Colorado Division of Reclamation Mining and Safety, Mountain Coal funded the entire Monument Dam project to ensure the highest degree of protection for the dam and the area residents. "They were instrumental in providing the permitting, engineering design and project management for the entire Monument Dam project. The employees of Mountain Coal are to be commended for their extraordinary efforts."

West Elk's preventative measures included stabilizing the landslide on the south abutment; buttressing the downstream face of the dam; installing a primary spillway valve and piping; installing trench drains, gravel filter, clay liner, piezometers and inclinometers; and rip-rapping the upstream face and emergency spillway. Also associated with the project was the installation of a remote survey station and five accelerometers for monitoring the dam.

The Minnesota Reservoir Company's Monument Dam, located near West Elk mine, was constructed in 1891 and the last enlargement to the dam was completed in 1936.

Mountain Coal Company's West Elk mine is located in Somerset, Colo. Nearly 450 people are employed at West Elk. West Elk has operated for more than nine years without a state SMCRA environmental violation.

St. Louis-based Arch Coal is one of the nation's largest and most efficient coal producers. The company's core business is providing U.S. power generators with cleaner-burning, low-sulfur coal for electric generation. Through its national network of mines, Arch supplies the fuel for approximately 6 percent of the electricity generated in the United States.