ST. LOUIS (June 29, 2007) – Arch Coal, Inc. (NYSE:ACI) will mark its 10-year anniversary on July 1, 2007.

"We are delighted to celebrate this anniversary with our customers, employees and other stakeholders, who together have made Arch Coal a world-class energy company," said Arch Coal's Chairman and Chief Executive Officer Steven F. Leer. "We set a high standard from the beginning and have demonstrated responsible and progressive leadership in the coal industry."

Arch Coal, Inc. was officially formed on July 1, 1997, through the merger of publicly traded Ashland Coal, Inc. and privately held Arch Mineral Corporation, whose origins date back to 1975 and 1969, respectively. With the completion of the merger, Arch became the leading producer of low-sulfur coal in the eastern United States.

During the past 10 years, Arch Coal has strategically expanded its position in clean-burning, low-sulfur coal regions. Today, Arch contributes roughly 11 percent of the annual U.S. coal supply, with 95 percent consumed by 128 U.S. electric power plants in 33 states and the remaining 5 percent consumed by domestic and international industrial and steel companies.

Leer has led Arch Coal since the day of its initial public offering, and previously served as president and chief executive officer of Arch Mineral Corporation.

"Electricity from Arch's coal has helped power America's growth for the past decade, fueling everything from lights to laptops," said Leer. "And with the help of clean-coal technologies, we expect Arch Coal to be right there providing fuel that meets the nation's economic and environmental objectives for many years to come."

St. Louis-based Arch Coal is one of the nation's largest 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 supplies the fuel for approximately 6 percent of the electricity generated in the United States.