UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT
Pursuant to Section 13 or 15(d)
of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported):  September 16, 2011 (September 13, 2011)

Arch Coal, Inc.

(Exact name of registrant as specified in its charter)

CityPlace One
One CityPlace Drive, Suite 300
St. Louis, Missouri 63141
(Address, including zip code, of principal executive offices)

Registrant’s telephone number, including area code:  (314) 994-2700

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o            Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o            Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o            Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o            Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01               Other Events.

On July 21, 2010, the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Act”) was enacted.  Section 1503 of the Act contains new reporting requirements regarding mine safety, including disclosing on a Current Report on Form 8-K the receipt of an imminent danger order under section 107(a) of the Federal Mine Safety and Health Act of 1977 (the “Mine Act”) issued by the Federal Mine Safety and Health Administration.

On September 13, 2011, Canyon Fuel Company LLC, a subsidiary of Arch Coal, Inc., received an imminent danger order under section 107(a) of the Mine Act stating that at it’s Dugout Canyon coal mine, a belt had not been locked or tagged out prior to two miners stepping on such belt.  In response to the order, mine personnel immediately took corrective action and the order was promptly terminated.

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Signatures

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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