SOMERSET, Colo., March 23, 2011 -- Arch Coal, Inc. (NYSE: ACI) today announced that Mountain Coal Company's West Elk mine employees were honored with a Colorado state safety award and two state environmental awards at the 113th National Western Mining Conference and Exhibition in Denver.

"West Elk turned out an outstanding 2010 performance, and garnered three statewide awards as a result," said John W. Eaves, Arch's president and chief operating officer. "We commend West Elk's employees for their significant accomplishments, which underscore their dedication to excellence and continuous improvement in safety and environmental performance."

The Colorado Division of Reclamation, Mining and Safety presented the 2010 Excellence in Safety Award to West Elk, the state's leader in mine safety among large underground coal mines in Colorado. West Elk's rate of 1.72 MSHA total incidents per 200,000 employee-hours was 70 percent lower than the national underground average of 5.91. This marks the second consecutive year that West Elk has been recognized as the safest underground coal mine in Colorado.

West Elk also was recognized by the Colorado Division of Reclamation, Mining and Safety for outstanding reclamation of an abandoned 1934 mining site. According to the Colorado Division of Reclamation, Mining and Safety, Mountain Coal Company and its West Elk mine employees were recognized with the "Outstanding Reclamation" award for successfully cleaning up and restoring the site and for its exemplary commitment to environmental stewardship.

The Colorado Department of Public Health and Environment, in cooperation with the Colorado Mining Association, recognized West Elk with Colorado's Senior Participant Award for its proactive methods of conserving water and preventing pollution. West Elk negotiates with shippers to use more efficient packaging materials, installed low-flow faucets and showerheads and conserves upland reservoir water.

Mountain Coal Company is a subsidiary of Arch Coal, Inc. Mountain Coal Company's West Elk mine is located in Somerset, Colo. More than 350 people are employed at West Elk. West Elk has operated for more than 11 years without a Colorado SMCRA violation.

U.S.-based Arch Coal is one of the largest coal producers in the world, with more than 160 million tons of coal sold in 2010. Arch's national network of mines supplies cleaner-burning, low-sulfur coal to customers on four continents, including U.S. and international power producers and steel manufacturers. Arch's companywide 2010 safety and environmental compliance records were the best in its history.