<PAGE>

                                                                 EXHIBIT 4.2
                                                                 -----------


                     MISSISSIPPI VALLEY BANCSHARES, INC.
          2002 NON-QUALIFIED STOCK OPTION PLAN (FIVE-YEAR OPTIONS)


                              OPTION AGREEMENT
                              ----------------

         This Option Agreement is entered into effective              , 20  ,
                                                         -------------    --
between Mississippi Valley Bancshares, Inc., a Missouri corporation
(the "Company"), and                              (the "Optionee").
                     ----------------------------

         WHEREAS, the Company deems it to be in its best interests to
promote the loyalty and facilitate the retention of certain officers of the
Company or its subsidiaries by offering them an increased incentive, in the
form of proprietary interests in the Company, to continue in the service of
the Company (including its subsidiaries) and increase their efforts for its
welfare, and

         WHEREAS, in furtherance of the above purposes the Company has
adopted its 2002 Stock Option Plan (Five-Year Options) (the "Plan"), and
desires to afford the Optionee an opportunity to purchase shares of its
common stock pursuant to the Plan as hereafter described,

         NOW, THEREFORE, in consideration of the premises and for other good
and valuable consideration, the parties hereto do hereby agree as follows:

         1.  Grant of Option. The Company hereby grants to the Optionee the
             ---------------
right and option (the "Option") to purchase all or any part of the number of
shares of the Common Stock of the Company set forth below (the "Shares"),
at the purchase price set forth below and on the other terms and conditions
herein set forth.

                    TOTAL NUMBER OF SHARES:
                                           --------

                    PURCHASE PRICE PER SHARE: $
                                               ---------

         2.  Dates When Option Exercisable.
             -----------------------------

             (a)  The Option shall vest and first become exercisable as follows:

                          % ON              , 200 ;
                       ---     -------------     -

                          % ON              , 200 ;
                       ---     -------------     -

                          % ON              , 200 ; AND
                       ---     -------------     -

                          % ON              , 200 .
                       ---     -------------     -

             (b)  Except as otherwise provided in paragraph 2(e), the Option
shall expire, to the extent it has not already been exercised, at the close
of business on the following date:

                    EXPIRATION DATE:               , 20
                                     --------------    --


<PAGE>
<PAGE>

             (c)  Notwithstanding paragraph 2(a) above, in the event of a
Change in Control, as hereinafter defined, the Option shall immediately vest
and become exercisable in full. For the purpose of this Option, "Change in
Control" shall mean (i) a merger or consolidation of the Company with or
into any other entity after which the holders of the voting stock of the
Company immediately prior to such merger or consolidation do not own, in
substantially the same proportions as they owned the voting stock of the
Company immediately prior to such merger or consolidation, at least a
majority of the voting power of the surviving or resulting entity
immediately following such merger or consolidation, or (ii) any change or
changes in the beneficial ownership of a majority of the Company's voting
stock within any one-year period, including any such change or changes
effected in whole or in part by the redemption of outstanding shares or the
issuance of new shares.

             (d)  Notwithstanding paragraph 2(a) above, in the event of
any transaction in which the holders of the Company's common stock shall
receive or may elect to receive either cash or securities of an entity
other than the Company, the Option shall vest and become exercisable in full
not less than 10 days before the last date upon which the stockholders of
the Company eligible to participate in, and receive the consideration
payable in, such transaction is determined, so as to permit the Optionee to
participate in, and receive the consideration payable in, the transaction
with respect to the Shares.

             (e)  Notwithstanding paragraph 2(b) and Section 3, in the event
of the death of the Optionee or termination of the Optionee's employment by
reason of his or her disability or incapacity, the Option may be exercised
(but only to the extent it was exercisable by the Optionee immediately prior
to his or her death or such termination of employment), by the Optionee's
personal representative, conservator (if any) or guardian (if any),
respectively, in the manner set forth below, for a period of 90 days after
the date of the Optionee's death or of such termination of employment.

         3.  Additional Condition to Exercise. Except as provided in
             --------------------------------
paragraph 2(e), the Option may be exercised only if the Optionee shall have
continuously served as an employee of the Company or its subsidiaries from
the date hereof to and including the date of exercise. It is expressly
understood and agreed that nothing herein is intended or shall be construed
as an employment contract or as implying any obligation on the part of the
Company to continue the Optionee's employment during a period sufficient to
permit the Option to vest.

         4.  Method of Exercising Option. The Optionee may exercise the
             ---------------------------
Option hereby granted on one or more occasions at his or her discretion, on
each occasion for all or any part of the Shares for which the Option is then
exercisable, by each time delivering to the Secretary of the Company a
written notice stating his or her election to exercise the Option and the
number of Shares to be purchased, together with cash or check in full
payment of the purchase price of the Shares then purchased, plus the amount
of any Federal and state withholding taxes payable by the Company as a
result of such exercise. The Option shall be deemed to be exercised only
upon receipt of such notice and payment by the Secretary.

         5.  Non-Transferability of Option. The Option shall not be
             -----------------------------
transferable, and may be exercised only by the Optionee or as otherwise
provided in paragraph 2(e) or by the Plan. More particularly, but without
limiting the generality of the foregoing, the Option may not be assigned,

                                     2


<PAGE>
<PAGE>

transferred, pledged or hypothecated in any way, other than by will or by
operation of law and shall not be subject to execution, attachment or
similar process. In the event of the bankruptcy of the Optionee or in the
event of any prohibited assignment, transfer, pledge, hypothecation or other
disposition of the Option, or the levy of any execution, attachment or
similar process upon the Option, the Option shall automatically expire and
shall be null and void.

         6.  Share Adjustments. In the event of any stock dividend on,
             -----------------
reclassification, split-up or combination of, or other change in, the
Company's Common Stock, then the number or kind of Shares subject to this
Option shall be correspondingly added to, reclassified, increased,
diminished or changed proportionately, without increase or decrease in the
aggregate purchase price of all Shares subject to Option before and after
such change.

         7.  No Rights of Optionee as Stockholder. The Optionee shall have
             ------------------------------------
no rights respecting this Option or the Shares issuable upon exercise of
this Option, except as expressly set forth herein; and the Optionee shall
have no rights as a stockholder with respect to such Shares until this
Option has been duly exercised in accordance with the terms hereof.

         8.  General. The Company shall at all times during the term of
             -------
the Option reserve and keep available such number of Shares as will be
sufficient to satisfy the requirements of this Option, and shall pay all
original issue and transfer taxes with respect to the issue and transfer of
Shares pursuant hereto and all other fees and expenses necessarily incurred
by the Company in connection therewith.

         IN WITNESS WHEREOF, the Company and the Optionee have executed this
Option Agreement as of the date first above written.

                             Company: MISSISSIPPI VALLEY BANCSHARES, INC.


                                      By:
                                         --------------------------------
                                         President
ATTEST:



-------------------------------



                             Optionee:
                                      -----------------------------------


                                     3