June 27, 2000



BOK Financial Corporation
Bank of Oklahoma Tower
P.O. Box 2300
Tulsa, OK  74192


     Re:  BOK Financial Corporation SEC Registration  Statement on Form S-8: BOK
          Financial  Corporation (Trading Symbol "BOKF"):  10,000 Shares of BOKF
          Common Stock to be Issued  Pursuant to the BOK  Financial  Corporation
          Thrift Plan for Hourly Employees.


Ladies and Gentleman:

     I have acted as counsel to BOK Financial Corporation ("BOKF") in connection
with BOKF's Registration  Statement on Form S-8 being filed on or about June 27,
2000 with the Securities and Exchange  Commission which respect to the shares of
Common Stock (the "Common Stock"),  $0.00006 par value, of BOKF,  authorized for
issuance under the BOK Financial Corporation Thrift Plan for Hourly Employees. I
have reviewed BOKF's  Registration  Statement on Form S-8, BOKF's Certificate of
Corporation,  BOKF's By-laws,  and such corporate  proceedings of BOKF as I have
deemed appropriate for purposes of rendering this opinion.  In my opinion,  upon
issuance  of the  shares  of  Common  Stock  pursuant  to the  terms  of the BOK
Financial Corporation Thrift Plan for Hourly Employees, such shares will be duly
and  validly  issued,  fully paid and  non-assessable.  I hereby  consent to the
filing of this opinion as an exhibit to the Registration Statement.



                                           Sincerely,

                                           /s/ Frederic Dorwart

                                           Frederic Dorwart