UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 14A
Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     )
Filed by the Registrant  x
Filed by a Party other than the Registrant  o
Check the appropriate box:
o	Preliminary Proxy Statement
o	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
o	Definitive Proxy Statement
x	Definitive Additional Materials
o	Soliciting Material under §240.14a-12
Arch Coal, Inc.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
Payment of Filing Fee (Check the appropriate box):
x	No fee required.
o	Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11.
	(1)		Title of each class of securities to which transaction applies:
	(2)		Aggregate number of securities to which transaction applies:
	(3)		Per unit price or other underlying value of transaction computed pursuant to Exchange Act Rule 0-11 (set forth the amount on which the filing fee is calculated and state how it was determined):
	(4)		Proposed maximum aggregate value of transaction:
	(5)		Total fee paid:
o	Fee paid previously with preliminary materials.
o	Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.
	(1)	Amount Previously Paid:
	(2)	Form, Schedule or Registration Statement No.:
	(3)	Filing Party:
	(4)	Date Filed:

*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on April 25, 2013. Meeting Information ARCH COAL, INC. Meeting Type: Annual Meeting For holders as of: March 1, 2013 Date: April 25, 2013 Time: 8:00 AM MT Location: Wright Hotel 300 Reata Drive Wright, Wyoming 82732 You are receiving this communication because you hold shares in the company named above. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side). We encourage you to access and review all of the important information contained in the proxy materials before voting. An admission ticket is required to attend the annual meeting of stockholders on April 25, 2013. This notice serves as an admission ticket to the annual meeting of stockholders on April 25, 2013. ARCH COAL, INC. ONE CITYPLACE DRIVE, SUITE 300 ST. LOUIS, MO 63141 M53639-P33140 See the reverse side of this notice to obtain proxy materials and voting instructions.

Before You Vote How to Access the Proxy Materials Proxy Materials Available to VIEW or RECEIVE: NOTICE AND PROXY STATEMENT ANNUAL REPORT How to View Online: Have the information that is printed in the box marked by the arrow (located on the following page) and visit: www.proxyvote.com. How to Request and Receive a PAPER or E-MAIL Copy: If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request: 1) BY INTERNET: www.proxyvote.com 2) BY TELEPHONE: 1-800-579-1639 3) BY E-MAIL*: sendmaterial@proxyvote.com * If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked by the arrow (located on the following page) in the subject line. . XXXX XXXX XXXX . XXXX XXXX XXXX Requests, instructions and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before April 11, 2013 to facilitate timely delivery. M53640-P33140 How To Vote Please Choose One of the Following Voting Methods Vote In Person: Many shareholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares. Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box marked by the arrow (located on the following page) available and follow the instructions. Vote By Mail or Phone: You can vote by mail or phone by requesting a paper copy of the materials, which will include a proxy card. . XXXX XXXX XXXX

Voting Items The Board of Directors unanimously recommends you vote "FOR" all the director nominees listed below in Proposal 1: 1. Election of Directors. Nominees: To be elected for terms expiring on 2016. 1a. Paul T. Hanrahan 1b. Steven F. Leer 1c. Theodore D. Sands The Board of Directors unanimously recommends you vote "FOR" the following Proposals 2-4: 2. Approval of the Arch Coal, Inc. Omnibus Incentive Plan (formerly known as the Arch Coal, Inc. 1997 Stock Incentive Plan). 3. Ratification of the appointment of Ernst & Young, LLP as independent registered public accounting firm for the fiscal year ending December 31, 2013. M53641-P33140 4. Advisory approval of the Company's named executive officer compensation.

M53642-P33140