Exhibit 16.1 Andersen Arthur Andersen LLP Suite 3100 1225 17th Street Denver CO 80202-5531 Tel 303 295 1900 Fax 303 291 9200 May 28, 2002 www.andersen.com Office of the Chief Accountant Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Dear Sir or Madam: We have read Item 4 included in the Form 8-K dated May 23, 2002 of St. Mary Land & Exploration Company to be filed with the Securities and Exchange Commission and are in agreement with the statements contained therein as they relate to Arthur Andersen LLP. Very truly yours, /S/ ARTHUR ANDERSEN LLP cc: Mr. Richard C. Norris Vice President - Finance St. Mary Land & Exploration Company