EXHIBIT 16 Office of the Chief Accountant Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 October 17, 2000 Dear Sir/ Madam: We have read the 4 paragraphs of Item 4 included in the Form 8-K dated October 17, 2000 of Farmers & Merchants Bancorp to be filed with the Securities and Exchange Commission and are in agreement with the statements contained therein. Very truly yours, ARTHUR ANDERSEN LLP By /s/ Jeffrey M. Jarczyk Copy to: Mr. John R. Olson, Executive Vice President & Chief Financial Officer, Farmers & Merchants Bancorp