Item 5.02 Departure of Directors or Certain Officers;
Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On December 13, 2012, Mr. Robert G. Potter notified Arch Coal, Inc. (the "Company") that he intends to retire from the Board of Directors of the Company, effective February 1, 2013, after serving on the board since 2001. The retirement is not related to any disagreement between Mr. Potter and the Company. Mr. Potter serves on the Company's Finance Committee and Personnel and Compensation Committee.

On December 13, 2012, Mr. James R. Boyd notified the Company that he intends to retire from the Board of Directors of the Company, effective February 1, 2013, after his long tenure on the board for more than 20 years. The retirement is not related to any disagreement between Mr. Boyd and the Company. Mr. Boyd serves as the Company's lead director, is chairman of the Company's Nominating and Corporate Governance Committee and is a member of the Company's Audit Committee.

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