POWER OF ATTORNEY

For Executing Forms 3, 4 and 5 and 144

Know all by these present, that the undersigned constitutes and
appoints each of Randall Erickson, Gina McBride, and Angela Peters,
signing singly, his true and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned Forms 3, 4 and 5
    in accordance with Section 16(a) of the Securities Exchange Act
    of 1934 and the rules thereunder;

(2) execute for and on behalf of the undersigned notices on Form 144
    in accordance with Rule 144 under the Securities Act of 1933;

(3) do and perform any and all acts for and on behalf of the
    undersigned which may be necessary or desirable to complete the
    execution of any such Forms 3,4 or 5 or Form 144 and the timely
    filing of such forms with the United States Securities and
    Exchange Commission and any other authority; and

(4) take any other action of any type whatsoever in connection with
    the foregoing which, in the opinion of such attorney-in-fact, may
    be of benefit to, in the best interest of, or legally required by,
    the undersigned, it being understood that the documents executed
    by such attorney-in-fact on behalf of the undersigned pursuant to
    the Power of Attorney shall be in such form and shall contain such
    terms and conditions as such attorney-in-fact may approve in his or
    her discretion.

The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform all and every act and thing whatsoever
requisite, necessary and proper to be done in the exercise of any of the
rights and powers herein granted, as fully to all intents and purposes
as such attorney-in-fact might or could do if personally present, with
full power of substitution or revocation, cause to be done by virtue of
this power of attorney and the rights and powers herein granted. The
undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not
assuming any of the undersigned's responsibilities to comply with Section
16 of the Securities Exchange Act of 1934 and the rules thereunder or Rule
144 under the Securities Act of 1933. This Power of Attorney shall be a
durable power of attorney and shall not be affected by subsequent disabiIity
or incapacity of the undersigned.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 19th day of December, 2005

/S/Peter M. Platten, III