ST. LOUIS (October 16, 2007) - Arch Coal, Inc. (NYSE:ACI) today announced that it has again achieved the ranks of the InformationWeek 500 list for its innovative use of wireless technologies to improve inventory management and for the creation of standardized customer-facing systems for shipment notification from its national network of mines.

The top 2007 InformationWeek 500 companies were revealed at a gala awards ceremony on September 19 in Tucson, Arizona. Arch Coal was the only coal producer ranked in the 2007 InformationWeek 500 list.

"We appreciate the continuing recognition for our progressive and adaptive information systems practices that contribute to productivity advances at all our operations," said Michael T. Abbene, Arch's vice president and chief information officer. "By keeping our I.S. priorities aligned with our business strategy, we add real value to the organization."

"The InformationWeek 500 honors today's leading companies who set the benchmark for business technology strategies and projects," said InformationWeek Vice President and Publisher John Siefert. "The companies on our list are some of the most innovative users of technology."

For nearly 20 years, InformationWeek has identified and honored the nation's most innovative users of information technology with its annual listing. The list is unique among corporate rankings because it spotlights the power of innovation in information technology, rather than simply identifying the biggest IT spenders. Additional details on InformationWeek and InformationWeek 500 can be found at www.informationweek.com/iw500/.

St. Louis-based Arch Coal is one of the nation's largest coal producers, with 2006 revenues of $2.5 billion. Through its national network of mines, Arch Coal provides the fuel for approximately 6 percent of the electricity generated in the United States. Arch has amassed numerous national and international awards for the innovative use of new technologies, including Business Week's Web Smart 50, CIO's Bold 100, and Baseline's 2007 Best U.S. Users of Technology.