EXHIBIT 99.1

PROXY
 
                          WESTAMERICA BANCORPORATION

            PROXY SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS OF
                          WESTAMERICA BANCORPORATION

         For the Special Meeting of Shareholders on February __, 1997

     The undersigned holder hereby authorizes David L. Payne to represent and
vote, as designated on the reverse side, all shares of Common Stock of
Westamerica Bancorporation which the undersigned would be entitled to vote at
the Special Meeting of Shareholders of said corporation to be held at
_________________, _______________, _________________, California at _______
_.m. on _____________, February __, 1997, upon the matters set forth on the
reverse side of this Proxy and described in the accompanying Joint Proxy
Statement/Prospectus.

     This Proxy, when properly executed, will be voted as directed herein by the
undersigned shareholder.  If no direction is indicated, this Proxy will be voted
FOR Item 1.

     Please Mark, Sign, Date and Mail This Proxy Promptly, Using the Enclosed 
Envelope.

COMMENTS/ADDRESS CHANGE:



                                 (Continued and to be signed on other side)


                                                                [X] Please mark
                                                                     your votes
                                                                      as this
          --------------    ------------------------------
              COMMON         DIVIDEND REINVESTMENT SHARES

The Board of Directors recommends a vote FOR Item 1.

                      FOR AGAINST ABSTAIN     I PLAN TO ATTEND MEETING      [_]
Item 1 - APPROVAL OF  [_]   [_]     [_]       If you check this box
THE AGREEMENT AND                             to the right an admission 
PLAN OF REORGANIZATION                        card will be sent to you.
AMONG WESTAMERICA
BANCORPORATION,                  
VALLICORP HOLDINGS,                           I have made an address change [_]
INC., AND VALLIWIDE                           or comment on the reverse 
BANK, AND AN AGREEMENT                        side of this proxy.    
OF MERGER BETWEEN                   
WESTAMERICA AND                               
VALLICORP AND THE                             Receipt is acknowledged of the 
TRANSACTIONS                                  Joint Proxy Statement/Prospectus
CONTEMPLATED THEREBY,                         for the Special Meeting.  Whether
INCLUDING, WITHOUT                            or not you expect to attend the 
LIMITATION, CERTAIN                           Special Meeting, you are urged to 
PROVISIONS BENEFITING                         execute and return this proxy, 
DIRECTORS, EXECUTIVE                          which may be revoked at any time 
OFFICERS AND EMPLOYEES                        prior to its use.
OF VALLICORP AND THE 
PROPOSED MERGER OF          
VALLICORP WITH AND 
INTO WESTAMERICA 


SIGNATURE(S)                                                    DATE
            ---------------------------------------------------     -----------

NOTE: Please sign as name appears hereon.  Joint owners should each sign.  When 
signing as attorney, executor, administrator, trustee or guardian, please give 
full title as such.



PROXY
 
                          WESTAMERICA BANCORPORATION
                       CONFIDENTIAL VOTING INSTRUCTIONS

        TO THE TRUSTEE SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS OF
                          WESTAMERICA BANCORPORATION

         For the Special Meeting of Shareholders on February __, 1997

     The undersigned holder hereby authorizes and instructs the Trustee of the
Westamerica Bancorporation Tax Deferred Savings/Retirement Plan to represent and
vote, as designated below, all shares of Common Stock of Westamerica
Bancorporation which the undersigned would be entitled to vote at the Special
Meeting of Shareholders of said corporation to be held at _________________,
_______________, _________________, California at _______ _.m. on _____________,
February __, 1997, upon the matters set forth on the reverse side of this Proxy
and described in the accompanying Joint Proxy Statement/Prospectus.

     These confidential voting instructions to the Trustee, when properly
executed, will be voted as directed herein by the undersigned shareholder. If no
instructions are received, the Trustee will vote all of the shares for which you
are entitled to provide instruction in the same proportion as shares for which
instructions are received.

     Please Mark, Sign, Date and Mail These Confidential Voting Instructions
Promptly, Using the Enclosed Envelope.

COMMENTS/ADDRESS CHANGE:



                                 (Continued and to be signed on other side)


 
                                                                [X] Please mark
                                                                     your votes
                                                                      as this
          --------------    ------------------------------
              COMMON         DIVIDEND REINVESTMENT SHARES

The Board of Directors recommends a vote FOR Item 1.

                      FOR AGAINST ABSTAIN     I PLAN TO ATTEND MEETING      [_]
Item 1 - APPROVAL OF  [_]   [_]     [_]       If you check this box
THE AGREEMENT AND                             to the right an admission 
PLAN OF REORGANIZATION                        card will be sent to you.
AMONG WESTAMERICA                  
BANCORPORATION,
VALLICORP HOLDINGS,                           
INC., AND VALLIWIDE                           
BANK, AND AN AGREEMENT                        
OF MERGER BETWEEN                   
WESTAMERICA AND                               
VALLICORP AND THE                             Receipt is acknowledged of the 
TRANSACTIONS                                  Joint Proxy Statement/Prospectus
CONTEMPLATED THEREBY,                         for the Special Meeting.  Whether
INCLUDING, WITHOUT                            or not you expect to attend the 
LIMITATION, CERTAIN                           Special Meeting, you are urged to 
PROVISIONS BENEFITING                         execute and return this proxy, 
DIRECTORS, EXECUTIVE                          which may be revoked at any time 
OFFICERS AND EMPLOYEES                        prior to its use.
OF VALLICORP AND THE 
PROPOSED MERGER OF          
VALLICORP WITH AND 
INTO WESTAMERICA 


SIGNATURE(S)                                                    DATE
            ---------------------------------------------------     -----------

NOTE: Please sign as name appears hereon.  Joint owners should each sign.  When 
signing as attorney, executor, administrator, trustee or guardian, please give 
full title as such.


                            FOLD AND DETACH HERE 

                     [LOGO OF WESTAMERICA BANCORPORATION]

Dear Participant: 

   As a participant in the Westamerica Bancorporation Tax Deferred
Savings/Retirement Plan (the "Plan"), you have an interest in the Special
Meeting of Shareholders of Westamerica Bancorporation which will be held on
_________, February ___, 1997 (the "Special Meeting"). You may direct the
Trustee of the Plan how to vote all full and fractional shares of Westamerica
Bancorporation stock standing to the credit of your individual account(s) (from
the Supplemental Retirement Plan Account, Employer Matching Contributions and
Employee Contributions) as of ___________, 199_ and your pro rata share of any
unallocated shares held by the Plan as of ________, 199_.
   For your information, we have enclosed a copy of the Joint Proxy
Statement/Prospectus supplied to shareholders of Westamerica Bancorporation. The
enclosed Joint Proxy Statement/Prospectus describes the proposal to be voted on
by the shareholders of Westamerica Bancorporation at the Special Meeting. The
Board of Directors of Westamerica Bancorporation recommends a vote FOR Proposal
1. Please instruct the Trustee how to vote on the proposal by indicating your
selection on the above Proxy. [The Trustee will keep your individual
instructions confidential and will not disclose them to Westamerica
Bancorporation or its officers and directors.]
   If the Trustee does not receive written instructions from you before the
close of business on ________, 199_, it will vote all of the shares for which
you are entitled to provide instruction in the same proportion as shares for
which instructions are received. Under the terms of the Plan, with respect to
fractional shares in plan accounts (from the Supplemental Retirement Plan
Account, Employer Matching Contributions and Employee Contributions), the
Trustee may pool the results of instructions received from all participants to
whom fractional shares have been allocated and vote such shares accordingly.
   Please instruct the Trustee how to vote your shares.  A return envelope is 
enclosed for your convenience.

                                       Sincerely yours,

                                       Mary Anne Bell
                                       Assistant Corporate Secretary