ST. LOUIS (September 29, 2008) - Arch Coal, Inc. (NYSE:ACI) today announced that it has been named one of America's best mid-cap stocks by Forbes magazine for showing a unique combination of growth, financial stability and promising forecasts.

"Arch's inclusion as one of America's best mid-cap stocks reinforces what we firmly believe - that ACI is well-positioned to serve the growing demand for reliable, secure and affordable energy in the United States and around the world," said Steven F. Leer, chairman and chief executive officer of Arch Coal. "We will continue to pursue excellence in three core values - safety, environmental stewardship and financial returns - in order to create long-term value for our shareholders."

The independent research firm, Audit Integrity, Inc., based its picks on 12-month and five-year sales, earnings, return on equity, plus estimated earnings growth and other information. More than 1,000 publicly traded stocks were considered for the Best 100 list. Arch was the only company listed from the U.S. coal industry.

Complete details behind the 100 Best Mid-Cap Stocks in America can be found in the special report posted at www.forbes.com.

St. Louis-based Arch Coal is one of the nation's largest coal producers, with revenues of $2.4 billion in 2007. The company's core business is providing U.S. power generators with cleaner-burning, low-sulfur coal for electric generation. Through its subsidiary operations in Wyoming, Utah, Colorado, West Virginia, Virginia and Kentucky, Arch provides the fuel for approximately 6 percent of the electricity generated in the United States. Arch Coal also holds the distinction as one of America's Most Trustworthy Companies of 2008.