CHARLESTON, W.Va., May 7, 2010 -- Arch Coal's Coal-Mac mining complex surpassed 3.0 million employee-hours and four years without a single lost-time injury on May 4, 2010.

Coal-Mac is located near Holden, W.Va., and employs approximately 300 people. Coal-Mac supplies more than 3 million tons of low-sulfur coal to domestic and international power producers each year.

"The employees of Coal-Mac prove their commitment to safety excellence each and every day," said Paul A. Lang, senior vice president of operations. "A perfect, four-year safety record clearly distinguishes Coal-Mac as a safety leader."

In the past five years, the employees of Coal-Mac have received 14 national and state awards for safety excellence, including a 2010 West Virginia Mountaineer Guardian Award.

St. Louis-based Arch Coal, Inc. (NYSE: ACI) is the second largest U.S. coal producer. Through its national network of mines, Arch supplies cleaner-burning, low-sulfur coal to fuel roughly 8 percent of the nation's electricity. Arch's lost-time incident rate was just one-fourth the national coal industry average during 2009, representing the company's best year on record.