ST. LOUIS (September 23, 2008) - Arch Coal, Inc. (NYSE: ACI) and its operating subsidiaries Coal-Mac, Inc. and Thunder Basin Coal Company were recognized today by the U.S. Department of Interior for demonstrating the nation's best stewardship practices of the past year.

The 2008 Gold and Bronze Good Neighbor Awards were presented to employees of Coal-Mac and Thunder Basin's Black Thunder mine for exemplary interaction, communication and involvement with the surrounding communities. Arch Coal subsidiaries have earned five national Good Neighbor Awards since the award was established in 2003.

"We strive to be good corporate citizens and community partners day in and day out," said Arch Coal's Chairman and Chief Executive Officer Steven F. Leer. "It's an honor to be recognized at the national level five times in five years for doing the right thing."

The U.S. Department of Interior's Office of Surface Mining presented Coal-Mac with the 2008 Gold Good Neighbor Award for its ongoing community service that included partnering on a 2007 mitigation project that created a new baseball field for Chapmanville High School. This joint project saved the Logan County School Board an estimated $1 million in construction-related costs.

Thunder Basin's Black Thunder mine was presented with the 2008 Bronze Good Neighbor award for its continuing efforts in local raptor research, habitat and education. The company sponsored a non-profit raptor education group, HawkQuest, for enhanced classroom and field experience of Campbell County ecology students on reclaimed mine lands. In addition, Black Thunder continues its efforts with the Nature Conservancy and the U.S. Forest Service in an international study of ferruginous hawks.

Coal-Mac is located in Mingo and Logan Counties of West Virginia. The mining complex employs nearly 300 people. Previously, Coal-Mac earned its first national Good Neighbor Award in 2004 and the American Coal Council's Excellence in Community Development Award in 2005.

Arch Coal and its Thunder Basin Coal Company employ more than 1,200 people in Wyoming. Located in Campbell County, Black Thunder mine is one of the largest and most efficient coal mines in the world. In 2006, Black Thunder mine earned its first national Good Neighbor Award, as well as the Wyoming Good Neighbor Award and Peck Community Achievement Award.

Since 1986, Arch Coal and its subsidiaries have won the coveted Director's Award three times, the National Award three times, the national Good Neighbor Award five times, as well as the Special 25th Anniversary Award. For a more complete list of Arch Coal's recent environmental and safety awards, visit www.archcoal.com/aboutus/awards.asp.

The U.S. Department of Interior's Office of Surface Mining (OSM) is the agency responsible for regulating the environmental impacts of coal production. Nominations from coal mine operators are first judged by state mining regulatory agencies, which forward state-level winners to OSM Headquarters for final judging at the national level. A panel of experts from OSM completes the final judging. More information is available at: http://www.osmre.gov.

St. Louis-based Arch Coal, Inc. is one of the largest U.S. coal producers. The company's core business is providing U.S. power generators with clean-burning, low-sulfur coal for electric generation. Through its national network of mines, Arch provides the fuel for approximately 6 percent of the electricity generated in the United States. More information is available at www.archcoal.com.