1 EXHIBIT 16 LETTER OF PREDECESSOR ACCOUNTANT To the Securities and Exchange Commission: We have read Item 9 included in the attached Annual Report on Form 10-K for the year ended December 31, 1997 of Arch Coal, Inc. to be filed with the Securities and Exchange Commission and are in agreement with the statements contained therein. /s/ ARTHUR ANDERSEN LLP ARTHUR ANDERSEN LLP St. Louis, Missouri March 16, 1998 53