Exhibit (99) PEOPLES BANCORP, INC. CERTIFICATION OF PERIODIC FINANCIAL REPORT PURSUANT TO 18 U.S.C. SECTION 1350 Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, the undersigned officers of Peoples Bancorp, Inc. (the "Company") certify that the Annual Report on Form 10-K of the Company for the fiscal year ended December 31, 2002 fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934 and information contained in that Form 10-K fairly presents, in all material respects, the financial condition and results of operations of the Company. Dated: March 27, 2003 /s/ Tony W. Wolfe ------------------ Tony W. Wolfe Chief Executive Officer Dated: March 27, 2003 /s/ A. Joseph Lampron ---------------------- A. Joseph Lampron Chief Financial Officer *This certification is made solely for purpose of 18 U.S.C. Section 1350, subject to the knowledge standard contained therein, and not for any other purpose.