EXHIBIT 99.906 CERT I, William G. Papesh, principal executive officer of the WM Trust I (the "Funds"), certify that: 1. The Form N-CSR of the Funds for the period ended October 31, 2005 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and 2. The information contained in the Form N-CSR of the Funds for the period ended October 31, 2005 fairly presents, in all material respects, the financial condition and results of operations of the Funds. By: /S/ WILLIAM G. PAPESH ---------------------- William G. Papesh President and Chief Executive Officer Principal Executive Officer Date: January 6, 2006 I, Jeffrey L. Lunzer, principal financial officer of the WM Trust I (the "Funds"), certify that: 1. The Form N-CSR of the Funds for the period ended October 31, 2005 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and 2. The information contained in the Form N-CSR of the Funds for the period ended October 31, 2005 fairly presents, in all material respects, the financial condition and results of operations of the Funds. By: /S/ JEFFREY L. LUNZER ----------------------- Jeffrey L. Lunzer Treasurer and Chief Financial Officer Principal Financial Officer Date: January 6, 2006