The company mines, processes, and markets bituminous and sub-bituminous coal with low sulfur content in the United States.

[16] In November 2009, Arch acquired the rights to mine 731 million tons of Otter Creek coal reserves in the northern Powder River Basin of Montana.

The company won a court approval allowing them to erase almost $5 billion in debt and left bankruptcy with $300 million in cash.

Shares of Core Natural Resources started trading on the New York Stock Exchange under the ticker symbol "CNR" the following day.

[30] Their West Virginia mining operations in the Appalachian Mountains were the subject of a critical documentary in 2002 on Now with Bill Moyers on PBS.

[31] Arch's Dal-Tex mining operations above the town of Blair, West Virginia were the subject of a 1998 U.S. News & World Report story "Shear Madness" by Penny Loeb.

No effect on related environmental values is more adverse than obliteration...Under a valley fill the water quality of the stream becomes zero.

"[34] As of 2012, the company reported that surface mining in Appalachian mountains accounted for roughly 4 percent of its annual coal production.

[6] Earthjustice, the Sierra Club, the Center for Biological Diversity and other environmental groups announced a campaign in 2015 against Arch Coal's mine project in the Sunset Roadless Area of Gunnison National Forest.

[39] In 2012, Arch Coal became the first energy company to earn the Conservation Legacy Award from the National Museum of Forest Service History.

The Museum of Forest Service History awarded this honor “in recognition of [Arch Coal’s] commitment to the protection of natural resources, wildlife and water quality values during mining and restoration operations”.