As filed with the Securities and Exchange Commission on June 22, 2006

                                                   Registration No. 333-106531


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                         POST-EFFECTIVE AMENDMENT NO. 1
                                       TO
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                            BOK FINANCIAL CORPORATION
             (Exact Name of Registrant as Specified in Its Charter)

                Oklahoma                                     73-1373454
    (State or Other Jurisdiction of                       (I.R.S. Employer
     Incorporation or Organization)                     Identification No.)

         Bank of Oklahoma Tower
            Tulsa, Oklahoma                                    74172
(Address of Principal Executive Offices)                     (Zip Code)

                              Amended and Restated
                            BOK Financial Corporation
                             2003 Stock Option Plan
                            (Full title of the Plan)

                                Tamara R. Wagman
                            Frederic Dorwart, Lawyers
                                124 E. 4th Street
                              Tulsa, Oklahoma 74103
                     Name and Address of Agent For Service)

                                 (918) 583-9922
          (Telephone Number, Including Area Code, of Agent for Service)

                         CALCULATION OF REGISTRATION FEE

<TABLE>
==================================================================================================================================
                                                                       Proposed                Proposed
                                                                       Maximum                 Maximum           Amount of
              Title of Each Class of            Amount to be        Offering Price            Aggregate         Registration
            Securities to be Registered         Registered(1)        Per Share(2)         Offering Price(2)          Fee
----------------------------------------------------------------------------------------------------------------------------------
<S>                                               <C>                  <C>                   <C>                   <C>
Common Stock, par value $.0006 per share (the     3,500,000            $48.08(2)             $168,280,000          $18,005.96
   "Common Stock")
----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

(1) The number of shares of Common Stock stated above consists of the aggregate
number of additional shares not previously registered upon the exercise of
options that may hereafter be granted under the Amended and Restated 2003 BOK
Financial Stock Option Plan (the "Plan"). The maximum number of shares that may
be sold upon the exercise of such options granted under the Plan is subject to
adjustment in accordance with certain anti-dilution and other provisions of the
Plan. Accordingly, pursuant to Rule 416 promulgated under the Securities Act of
1933, as amended (the "Securities Act"), this Registration Statement covers, in
addition to the number of shares stated above, an indeterminate number of shares
that may be subject to grant or otherwise issuable after the operation of any
such anti-dilution and other provisions.

(2) This calculation is made solely for the purpose of determining the
registration fee pursuant to Rule 457(h) under the Securities Act based on the
average of the high and low sale prices per share of the Common Stock on the
Nasdaq National Market on May 26, 2006.

<PAGE>

                      REGISTRATION OF ADDITIONAL SECURIITES

     This  Post-Effective  Amendment No. 1 to the Registration  Statement hereby
registers  3,500,000  additional  shares of Common Stock pursuant to the Plan. A
Registration Statement on Form S-8 (No. 333-106531) registering 2,000,000 shares
of Common  Stock under the Plan was filed with the  Commission  on June 26, 2003
(the "Registration  Statement").  Pursuant to General Instruction E of Form S-8,
the contents of the above-listed  Registration Statement, as amended, are hereby
incorporated  herein by  reference  and the  information  required by Part II is
omitted, except for Items 3 and 8 which are updated as follows:

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference

     The following  documents  filed by the  Registrant  with the Commission are
incorporated herein by reference:

1.    The Registrant's Annual Report on Form 10-K, as subsequently amended on
      Form 10-K/A on June 8, 2006, for the fiscal year ended December 31, 2005
      ("Fiscal 2005");

2.    The Registrant's Quarterly Report on Form 10-Q for the quarter ended March
      31, 2006;

3.    All other reports of the Registrant filed pursuant to Section 13(a) or
      15(d) of the Securities Exchange act of 1934, as amended (the "Exchange
      Act"), since the end of Fiscal 2005; and

4.    The descriptions of the Registrant's Common Stock that are contained in
      the Registration Statements filed under Section 12 of the Exchange Act,
      including any amendment or report filed for the purpose of updating such
      description.

     All documents  subsequently  filed by the  Registrant  pursuant to Sections
13(a),  13(c),  14 and  15(d)  of the  Exchange  Act  after  the  date  of  this
Registration  Statement  on Form S-8 and  prior to such  time as the  Registrant
files a post-effective amendment to this Registration Statement on Form S-8 that
indicates  that  all  securities   offered  hereby  have  been  sold,  or  which
deregisters  all such securities  then remaining  unsold,  shall be deemed to be
incorporated by reference herein and to be a part hereof from the date of filing
such reports and documents.  Any statement contained in a document  incorporated
or deemed to be incorporated by reference  herein shall be deemed to be modified
or superseded for purposes of this  Registration  Statement to the extent that a
statement contained in any subsequently-filed document that also is deemed to be
incorporated by reference herein modifies or supersedes such statement.

Item 8.  Exhibits

     The following  exhibits have been filed (except where otherwise  indicated)
as part of this Registration Statement:

 Exhibit No.   Description
-------------- ------------------------------------------------------------
       4.4     Amended and Restated 2003 BOK Financial Corporation Stock
               Option Plan (filed on Form DEF 14A on March 22, 2006)

       5.1     Opinion of Frederic Dorwart, Lawyers*

      23.1     Consent of Frederic Dorwart, Lawyers (included in Exhibit 5.1)*

      23.2     Consent of Ernst & Young L.L.P. *

               * Filed herewith

                                   SIGNATURES

     Pursuant to the  requirements of the Securities Act of 1933, the Registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for filing this  Post-Effective  Amendment  No. 1 to  Registration
Statement  on Form S-8,  and has duly caused this  Registration  Statement to be
signed on its behalf by the undersigned,  thereunto duly authorized, in the Town
of Tulsa,  State of Oklahoma,  on this 19th day of June,  2006.

                              BOK Financial Corporation

                              By:         /s/ Stanley A. Lybarger
                                  ---------------------------------------------
                                             Stanley A. Lybarger
                                      President and Chief Executive Officer


     Pursuant to the  requirements  of the  Securities  Act of 1933, as amended,
this  Post-Effective  Amendment No. 1 to Registration  Statement on Form S-8 has
been signed by the following  persons  pursuant to the Power of Attorney granted
to Mr.  George  B.  Kaiser  on  June  24,  2003,  including  the  power  to file
post-effective amendments:


Signature                              Title                           Date

/s/ George B. Kaiser          Chairman of the Board                June 19, 2006
--------------------------
George B. Kaiser

/s/ Stanley A. Lybarger       President, Chief Executive Officer   June 19, 2006
--------------------------    and Director
Stanley A. Lybarger

/s/ Steven E. Nell            Executive Vice President and         June 19, 2006
--------------------------    Chief Financial Officer
Steven E. Nell

/s/ John C. Morrow            Senior Vice President and Director   June 19, 2006
--------------------------    of Financial Accounting and Reporting
John C. Morrow

/s/ POA C. Fred Ball, Jr.     Director                             June 19, 2006
--------------------------
C. Fred Ball, Jr.

/s/ POA Sharon J. Bell        Director                             June 19, 2006
--------------------------
Sharon J. Bell

/s/ POA Peter Boylan, III     Director                             June 19, 2006
--------------------------
Peter Boylan, III

/s/ POA Robert G. Greer       Director                             June 19, 2006
--------------------------
Robert G. Greer

/s/ POA David F. Griffin      Director                             June 19, 2006
--------------------------
David F. Griffin

/s/ POA V. Burns Hargis       Director                             June 19, 2006
--------------------------
V. Burns Hargis

/s/POA E. Carey Joullian,IV   Director                             June 19, 2006
--------------------------
E. Carey Joullian, IV

/s/ POA David L. Kyle         Director                             June 19, 2006
--------------------------
David L. Kyle

/s/ POA Robert J. LaFortune   Director                             June 19, 2006
--------------------------
Robert J. LaFortune

/s/ POA Steven J. Malcolm     Director                             June 19, 2006
--------------------------
Steven J. Malcolm


THE PLAN. Pursuant to the requirements of the Securities Act of 1933, the
trustees (or other persons who administer the employee benefit plan) have duly
caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Tulsa, State of Oklahoma,
as of June 19, 2006.

                            AMENDED AND RESTATED
                            BOK FINANCIAL CORPORATION
                            2003 STOCK OPTION PLAN


                         By    /s/ George B. Kaiser
                              -------------------------------------------------
                              George  B.  Kaiser,  Chairman  of the  Board  of
                              BOK  Financial  Corporation  and Administrator of
                              the BOKF 2003 Plan


                         By    /s/ Stanley A. Lybarger
                              -------------------------------------------------
                              Stanley A.  Lybarger,  President,  Chief
                              Executive  Officer  and  Director of BOK
                              Financial Corporation and Administrator of the
                              BOKF 2003 Plan

<PAGE>

                                INDEX TO EXHIBITS

 Exhibit No.    Description
--------------- ---------------------------------------------------------------
        4.4     Amended and Restated 2003 BOK Financial Corporation Stock
                Option Plan (filed on Form DEF 14A on March 22, 2006)

        5.1     Opinion of Frederic Dorwart, Lawyers*

       23.1     Consent of Frederic Dorwart, Lawyers (included in Exhibit 5.1)*

       23.2     Consent of Ernst & Young L.L.P. *

                * Filed herewith

<PAGE>


                                   Exhibit 5.1


June 19, 2006

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"):  Shares of BOKF Common Stock
     to be Issued Pursuant to the Amended and Restated BOK Financial Corporation
     2003 Stock Option Plan.


Ladies and Gentleman:

     I have acted as counsel to BOK Financial Corporation ("BOKF") in connection
with BOKF's Post-Effective  Amendment No. 1 to the Registration  Statement being
filed on or about May 31, 2006 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 Amended and Restated BOK Financial
Corporation 2003 Stock Option Plan. I have reviewed Post-Effective Amendment No.
1 to the 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 Amended and Restated
BOK Financial  Corporation  2003 Stock Option Plan, 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


<PAGE>

                                      23.1

                      Consent of Frederic Dorwart, Lawyers

                  Included in the Opinion Filed as Exhibit 5.1


<PAGE>

                                      23.2

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the Registration Statement (Form
S-8 No.  333-106531)  pertaining  to the BOK  Financial  Corporation  2003 Stock
Option  Plan  of  our  reports  dated  March  10,  2006,  with  respect  to  the
consolidated  financial statements of BOK Financial  Corporation included in its
Annual  Report  (Form  10-K) as  subsequently  amended by Form 10-K/A on June 8,
2006,  for the fiscal year ended  December 31, 2005,  BOK Financial  Corporation
management's  assessment of the effectiveness of internal control over financial
reporting, and the effectiveness of internal control over financial reporting of
BOK Financial Corporation, filed with the Securities and Exchange Commission.


                                              /s/ ERNST & YOUNG LLP




Tulsa, Oklahoma
June 19, 2006
[{"type": "S-8", "sequence": "1", "filename": "s-8stkoptplan2003amend.txt", "description": "2003 STOCK OPTION PLAN", "secsgml_size_bytes": 14911}]
{"company-data": {"conformed-name": "BOK FINANCIAL CORP ET AL", "cik": "0000875357", "assigned-sic": "6021", "irs-number": "731373454", "state-of-incorporation": "OK", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-135224", "film-number": "06919395"}, "business-address": {"street1": "BANK OF OKLAHOMA TOWER", "street2": "PO BOX 2300", "city": "TULSA", "state": "OK", "zip": "74192", "phone": "9185953025"}, "mail-address": {"street1": "BANK OF OKLAHOMA TOWER", "street2": "P O BOX 2300", "city": "TULSA", "state": "OK", "zip": "74192"}}
As filed with the Securities and Exchange Commission on June 22, 2006

                                                   Registration No. 333-106531

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                         POST-EFFECTIVE AMENDMENT NO. 1
                                       TO
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                            BOK FINANCIAL CORPORATION
             (Exact Name of Registrant as Specified in Its Charter)

                Oklahoma                                     73-1373454
    (State or Other Jurisdiction of                       (I.R.S. Employer
     Incorporation or Organization)                     Identification No.)

         Bank of Oklahoma Tower
            Tulsa, Oklahoma                                    74172
(Address of Principal Executive Offices)                     (Zip Code)

                              Amended and Restated
                            BOK Financial Corporation
                             2003 Stock Option Plan
                            (Full title of the Plan)

                                Tamara R. Wagman
                            Frederic Dorwart, Lawyers
                                124 E. 4th Street
                              Tulsa, Oklahoma 74103
                     Name and Address of Agent For Service)

                                 (918) 583-9922
          (Telephone Number, Including Area Code, of Agent for Service)

                         CALCULATION OF REGISTRATION FEE

==================================================================================================================================
                                                                       Proposed                Proposed
                                                                       Maximum                 Maximum           Amount of
              Title of Each Class of            Amount to be        Offering Price            Aggregate         Registration
            Securities to be Registered         Registered(1)        Per Share(2)         Offering Price(2)          Fee
----------------------------------------------------------------------------------------------------------------------------------
Common Stock, par value $.0006 per share (the     3,500,000            $48.08(2)             $168,280,000          $18,005.96
   "Common Stock")
----------------------------------------------------------------------------------------------------------------------------------
(1) The number of shares of Common Stock stated above consists of the aggregate
number of additional shares not previously registered upon the exercise of
options that may hereafter be granted under the Amended and Restated 2003 BOK
Financial Stock Option Plan (the "Plan"). The maximum number of shares that may
be sold upon the exercise of such options granted under the Plan is subject to
adjustment in accordance with certain anti-dilution and other provisions of the
Plan. Accordingly, pursuant to Rule 416 promulgated under the Securities Act of
1933, as amended (the "Securities Act"), this Registration Statement covers, in
addition to the number of shares stated above, an indeterminate number of shares
that may be subject to grant or otherwise issuable after the operation of any
such anti-dilution and other provisions.

(2) This calculation is made solely for the purpose of determining the
registration fee pursuant to Rule 457(h) under the Securities Act based on the
average of the high and low sale prices per share of the Common Stock on the
Nasdaq National Market on May 26, 2006.
REGISTRATION OF ADDITIONAL SECURIITES

     This  Post-Effective  Amendment No. 1 to the Registration  Statement hereby
registers  3,500,000  additional  shares of Common Stock pursuant to the Plan. A
Registration Statement on Form S-8 (No. 333-106531) registering 2,000,000 shares
of Common  Stock under the Plan was filed with the  Commission  on June 26, 2003
(the "Registration  Statement").  Pursuant to General Instruction E of Form S-8,
the contents of the above-listed  Registration Statement, as amended, are hereby
incorporated  herein by  reference  and the  information  required by Part II is
omitted, except for Items 3 and 8 which are updated as follows:

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference

     The following  documents  filed by the  Registrant  with the Commission are
incorporated herein by reference:

1.    The Registrant's Annual Report on Form 10-K, as subsequently amended on
      Form 10-K/A on June 8, 2006, for the fiscal year ended December 31, 2005
      ("Fiscal 2005");

2.    The Registrant's Quarterly Report on Form 10-Q for the quarter ended March
      31, 2006;

3.    All other reports of the Registrant filed pursuant to Section 13(a) or
      15(d) of the Securities Exchange act of 1934, as amended (the "Exchange
      Act"), since the end of Fiscal 2005; and

4.    The descriptions of the Registrant's Common Stock that are contained in
      the Registration Statements filed under Section 12 of the Exchange Act,
      including any amendment or report filed for the purpose of updating such
      description.

     All documents  subsequently  filed by the  Registrant  pursuant to Sections
13(a),  13(c),  14 and  15(d)  of the  Exchange  Act  after  the  date  of  this
Registration  Statement  on Form S-8 and  prior to such  time as the  Registrant
files a post-effective amendment to this Registration Statement on Form S-8 that
indicates  that  all  securities   offered  hereby  have  been  sold,  or  which
deregisters  all such securities  then remaining  unsold,  shall be deemed to be
incorporated by reference herein and to be a part hereof from the date of filing
such reports and documents.  Any statement contained in a document  incorporated
or deemed to be incorporated by reference  herein shall be deemed to be modified
or superseded for purposes of this  Registration  Statement to the extent that a
statement contained in any subsequently-filed document that also is deemed to be
incorporated by reference herein modifies or supersedes such statement.

Item 8.  Exhibits

     The following  exhibits have been filed (except where otherwise  indicated)
as part of this Registration Statement:

 Exhibit No.   Description
-------------- ------------------------------------------------------------
       4.4     Amended and Restated 2003 BOK Financial Corporation Stock
               Option Plan (filed on Form DEF 14A on March 22, 2006)

       5.1     Opinion of Frederic Dorwart, Lawyers*

      23.1     Consent of Frederic Dorwart, Lawyers (included in Exhibit 5.1)*

      23.2     Consent of Ernst & Young L.L.P. *

               * Filed herewith

                                   SIGNATURES

     Pursuant to the  requirements of the Securities Act of 1933, the Registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for filing this  Post-Effective  Amendment  No. 1 to  Registration
Statement  on Form S-8,  and has duly caused this  Registration  Statement to be
signed on its behalf by the undersigned,  thereunto duly authorized, in the Town
of Tulsa,  State of Oklahoma,  on this 19th day of June,  2006.

                              BOK Financial Corporation

                              By:         /s/ Stanley A. Lybarger
                                  ---------------------------------------------
                                             Stanley A. Lybarger
                                      President and Chief Executive Officer

     Pursuant to the  requirements  of the  Securities  Act of 1933, as amended,
this  Post-Effective  Amendment No. 1 to Registration  Statement on Form S-8 has
been signed by the following  persons  pursuant to the Power of Attorney granted
to Mr.  George  B.  Kaiser  on  June  24,  2003,  including  the  power  to file
post-effective amendments:

Signature                              Title                           Date

/s/ George B. Kaiser          Chairman of the Board                June 19, 2006
--------------------------
George B. Kaiser

/s/ Stanley A. Lybarger       President, Chief Executive Officer   June 19, 2006
--------------------------    and Director
Stanley A. Lybarger

/s/ Steven E. Nell            Executive Vice President and         June 19, 2006
--------------------------    Chief Financial Officer
Steven E. Nell

/s/ John C. Morrow            Senior Vice President and Director   June 19, 2006
--------------------------    of Financial Accounting and Reporting
John C. Morrow

/s/ POA C. Fred Ball, Jr.     Director                             June 19, 2006
--------------------------
C. Fred Ball, Jr.

/s/ POA Sharon J. Bell        Director                             June 19, 2006
--------------------------
Sharon J. Bell

/s/ POA Peter Boylan, III     Director                             June 19, 2006
--------------------------
Peter Boylan, III

/s/ POA Robert G. Greer       Director                             June 19, 2006
--------------------------
Robert G. Greer

/s/ POA David F. Griffin      Director                             June 19, 2006
--------------------------
David F. Griffin

/s/ POA V. Burns Hargis       Director                             June 19, 2006
--------------------------
V. Burns Hargis

/s/POA E. Carey Joullian,IV   Director                             June 19, 2006
--------------------------
E. Carey Joullian, IV

/s/ POA David L. Kyle         Director                             June 19, 2006
--------------------------
David L. Kyle

/s/ POA Robert J. LaFortune   Director                             June 19, 2006
--------------------------
Robert J. LaFortune

/s/ POA Steven J. Malcolm     Director                             June 19, 2006
--------------------------
Steven J. Malcolm

THE PLAN. Pursuant to the requirements of the Securities Act of 1933, the
trustees (or other persons who administer the employee benefit plan) have duly
caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Tulsa, State of Oklahoma,
as of June 19, 2006.

                            AMENDED AND RESTATED
                            BOK FINANCIAL CORPORATION
                            2003 STOCK OPTION PLAN

                         By    /s/ George B. Kaiser
                              -------------------------------------------------
                              George  B.  Kaiser,  Chairman  of the  Board  of
                              BOK  Financial  Corporation  and Administrator of
                              the BOKF 2003 Plan

                         By    /s/ Stanley A. Lybarger
                              -------------------------------------------------
                              Stanley A.  Lybarger,  President,  Chief
                              Executive  Officer  and  Director of BOK
                              Financial Corporation and Administrator of the
                              BOKF 2003 Plan
INDEX TO EXHIBITS

 Exhibit No.    Description
--------------- ---------------------------------------------------------------
        4.4     Amended and Restated 2003 BOK Financial Corporation Stock
                Option Plan (filed on Form DEF 14A on March 22, 2006)

        5.1     Opinion of Frederic Dorwart, Lawyers*

       23.1     Consent of Frederic Dorwart, Lawyers (included in Exhibit 5.1)*

       23.2     Consent of Ernst & Young L.L.P. *

                * Filed herewith
Exhibit 5.1

June 19, 2006

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"):  Shares of BOKF Common Stock
     to be Issued Pursuant to the Amended and Restated BOK Financial Corporation
     2003 Stock Option Plan.

Ladies and Gentleman:

     I have acted as counsel to BOK Financial Corporation ("BOKF") in connection
with BOKF's Post-Effective  Amendment No. 1 to the Registration  Statement being
filed on or about May 31, 2006 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 Amended and Restated BOK Financial
Corporation 2003 Stock Option Plan. I have reviewed Post-Effective Amendment No.
1 to the 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 Amended and Restated
BOK Financial  Corporation  2003 Stock Option Plan, 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
23.1

                      Consent of Frederic Dorwart, Lawyers

                  Included in the Opinion Filed as Exhibit 5.1
23.2

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the Registration Statement (Form
S-8 No.  333-106531)  pertaining  to the BOK  Financial  Corporation  2003 Stock
Option  Plan  of  our  reports  dated  March  10,  2006,  with  respect  to  the
consolidated  financial statements of BOK Financial  Corporation included in its
Annual  Report  (Form  10-K) as  subsequently  amended by Form 10-K/A on June 8,
2006,  for the fiscal year ended  December 31, 2005,  BOK Financial  Corporation
management's  assessment of the effectiveness of internal control over financial
reporting, and the effectiveness of internal control over financial reporting of
BOK Financial Corporation, filed with the Securities and Exchange Commission.

                                              /s/ ERNST & YOUNG LLP

Tulsa, Oklahoma
June 19, 2006