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): May 1, 2012

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 7.01               Regulation FD Disclosure.

On May 1, 2012, Arch Coal, Inc. issued a press release entitled “Arch Western Finance, LLC Announces Tender Offer and Consent Solicitation for Its 6 ¾% Senior Notes Due 2013.”  The press release is attached as Exhibit 99.1 hereto and is hereby incorporated by reference.

The information contained in Item 7.01 and the exhibits attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall they be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended (the “Securities Act”) or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01               Financial Statements and Exhibits.

(d)                                 Exhibits

The following exhibits are attached hereto and filed herewith.

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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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Exhibit Index

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Exhibit 99.1

Arch Western Finance, LLC Announces Tender Offer and Consent Solicitation for Its 6 ¾% Senior Notes Due 2013

ST. LOUIS (May 1, 2012) — Arch Coal, Inc. (NYSE:ACI) today announced that Arch Western Finance, LLC (“Arch Western Finance”), its indirect subsidiary, commenced a cash tender offer (the “Tender Offer”) for any and all of its outstanding $450,000,000 aggregate principal amount of 6 ¾% Senior Notes due 2013 (CUSIP Nos. 03939RAB6, 03939RAA8 and U22142AB6) (the “Notes”).  In connection with the Tender Offer, Arch Western Finance is soliciting consents (the “Consent Solicitation”) from the holders of the Notes for certain proposed amendments to the indenture governing the Notes (the “Indenture”) that would eliminate most of the covenants and certain default provisions applicable to the Notes, as well as reduce the minimum notice period in the optional redemption provision of the Notes from 30 days to three days.  Holders who tender their Notes will be deemed to consent to the proposed amendments and holders may not deliver consents to the proposed amendments without tendering their Notes in the Tender Offer.  The terms and conditions of the Tender Offer and Consent Solicitation are described in an Offer to Purchase and Consent Solicitation Statement, dated May 1, 2012 (the “Statement”), and a related Consent and Letter of Transmittal, which are being sent to holders of Notes.

Holders of Notes must validly tender and not validly withdraw their Notes and provide their consents to the proposed amendments to the Indenture on or before 5:00 p.m., New York City time, on May 14, 2012, unless extended (such date and time, as the same may be extended, the “Consent Expiration”) in order to be eligible to receive the Total Consideration.  Holders of Notes who validly tender and do not validly withdraw their Notes and provide their consents to the proposed amendments to the Indenture after the Consent Expiration and on or before the Expiration Time (as defined below) will be eligible to receive only the Tender Offer Consideration, which is equal to the Total Consideration minus the Consent Payment.  In addition to the Total Consideration or the Tender Offer Consideration, as applicable, holders whose Notes are accepted for purchase in the Tender Offer will receive accrued and unpaid interest from the most recent interest payment date on the Notes up to, but not including, the applicable settlement date.

The Tender Offer contemplates an early settlement option for Notes that are validly tendered and not validly withdrawn prior to the Consent Expiration and accepted for purchase.  The Tender Offer will expire at 11:59 p.m., New York City time, on May 29, 2012, unless extended (such date and time, as the same may be extended, the “Expiration Time”), with final settlement expected to occur on the following

Arch Coal, Inc.

business day after the Expiration Time.  As set forth in the Statement, validly tendered Notes may be validly withdrawn and consents may be revoked at any time on or before 5:00 p.m., New York City time, on May 14, 2012, unless extended.

Any extension, termination or amendment of the Tender Offer or the Consent Solicitation will be followed as promptly as practicable by a public announcement thereof.  The consummation of the Tender Offer is not conditioned upon any minimum amount of Notes being tendered, but is conditioned upon the satisfaction or waiver of the conditions set forth in the Statement, which include: (i) the execution of a supplemental indenture implementing the proposed amendments to the Indenture upon receipt of consents thereto from holders of a majority in principal amount of the outstanding Notes, excluding any Notes held by Arch Western Finance and its affiliates, (ii) the consummation of a financing transaction, the availability and terms of which will be determined by market conditions and other factors at the time any such transaction is completed, and (iii) certain other customary conditions, in each case as more fully described in the Statement.

Arch Western Finance’s obligations to accept any Notes tendered and to pay the applicable consideration for them are set forth solely in the Statement and the related Consent and Letter of Transmittal.  This news release is not an offer to purchase, a solicitation of an offer to sell, or a solicitation of consents with respect to any securities.  The Tender Offer and Consent Solicitation are made only by, and pursuant to the terms of, the Statement and the related Consent and Letter of Transmittal, and the information in this news release is qualified by reference thereto.  None of Arch Coal, Arch Western Finance, the Dealer Manager and Solicitation Agent or the Depositary and Information Agent makes any recommendation in connection with the Tender Offer and the Consent Solicitation.  Subject to applicable law, Arch Western Finance may amend, extend or, subject to certain conditions, terminate the Tender Offer or the Consent Solicitation.  In addition, this news release does not constitute a notice of redemption of the Notes under the optional redemption provisions of the Indenture.

BofA Merrill Lynch is the Dealer Manager and Solicitation Agent for the Tender Offer and the Consent Solicitation.  Persons with questions regarding the Tender Offer or the Consent Solicitation should contact BofA Merrill Lynch at (888) 292-0070 (toll-free) or (980) 387-3907 (collect).  Requests for copies of the Statement, the related Consent and Letter of Transmittal, the Indenture and other related materials should be directed to Global Bondholder Services Corporation, the Depositary and Information Agent for the Tender Offer and the Consent Solicitation, at (212) 430-3774 (for banks and brokers only) or (866) 387-1500 (for all others and toll-free).

U.S.-based Arch Coal is a top five global coal producer and marketer, with 157 million tons of coal sold in 2011.  Arch is the most diversified American coal company, with more than 20 active mining complexes across every major U.S. coal supply basin.  Its core business is supplying cleaner-burning, low-sulfur thermal and metallurgical coal to power generators and steel manufacturers on five continents.  In 2011, Arch continued to lead the U.S. coal industry in safety performance and environmental compliance among large, diversified producers.

Forward-Looking Statements:  This press release contains “forward-looking statements” — that is, statements related to future, not past, events.  In this context, forward-looking statements often address our expected future business and financial performance, and often contain words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” or “will.”  Forward-looking statements by their nature address matters that are, to different degrees, uncertain.  For us, particular uncertainties arise from changes in the demand for our coal by the domestic electric generation industry; from legislation and regulations relating to the Clean Air Act and other environmental

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initiatives; from operational, geological, permit, labor and weather-related factors; from fluctuations in the amount of cash we generate from operations; from future integration of acquired businesses; and from numerous other matters of national, regional and global scale, including those of a political, economic, business, competitive or regulatory nature.  These uncertainties may cause our actual future results to be materially different than those expressed in our forward-looking statements.  We do not undertake to update our forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required by law.  For a description of some of the risks and uncertainties that may affect our future results, you should see the risk factors described from time to time in the reports we file with the Securities and Exchange Commission.

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