Exhibit 99 (b)

Reports of Ernst & Young LLP, Independent Registered Public Accounting Firm

Report on Effectiveness of Internal Control over Financial Reporting

The Board of Directors and Shareholders of BOK Financial Corporation

We have audited management's assessment, included in the accompanying
Management's Report on Internal Control over Financial Reporting, that BOK
Financial Corporation maintained effective internal control over financial
reporting as of December 31, 2005, based on criteria established in Internal
Control--Integrated Framework issued by the Committee of Sponsoring
Organizations of the Treadway Commission (the COSO criteria). BOK Financial
Corporation's management is responsible for maintaining effective internal
control over financial reporting and for its assessment of the effectiveness of
internal control over financial reporting. Our responsibility is to express an
opinion on management's assessment and an opinion on the effectiveness of the
company's internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company
Accounting Oversight Board (United States). Those standards require that we plan
and perform the audit to obtain reasonable assurance about whether effective
internal control over financial reporting was maintained in all material
respects. Our audit included obtaining an understanding of internal control over
financial reporting, evaluating management's assessment, testing and evaluating
the design and operating effectiveness of internal control, and performing such
other procedures as we considered necessary in the circumstances. We believe
that our audit provides a reasonable basis for our opinion.

A company's internal control over financial reporting is a process designed to
provide reasonable assurance regarding the reliability of financial reporting
and the preparation of financial statements for external purposes in accordance
with generally accepted accounting principles. A company's internal control over
financial reporting includes those policies and procedures that (1) pertain to
the maintenance of records that, in reasonable detail, accurately and fairly
reflect the transactions and dispositions of the assets of the company; (2)
provide reasonable assurance that transactions are recorded as necessary to
permit preparation of financial statements in accordance with generally accepted
accounting principles, and that receipts and expenditures of the company are
being made only in accordance with authorizations of management and directors of
the company; and (3) provide reasonable assurance regarding prevention or timely
detection of unauthorized acquisition, use, or disposition of the company's
assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting
may not prevent or detect misstatements. Also, projections of any evaluation of
effectiveness to future periods are subject to the risk that controls may become
inadequate because of changes in conditions, or that the degree of compliance
with the policies or procedures may deteriorate.

In our opinion, management's assessment that BOK Financial Corporation
maintained effective internal control over financial reporting as of December
31, 2005, is fairly stated, in all material respects, based on the COSO
criteria. Also, in our opinion, BOK Financial Corporation maintained, in all
material respects, effective internal control over financial reporting as of
December 31, 2005, based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company
Accounting Oversight Board (United States), the 2005 consolidated financial
statements of BOK Financial Corporation and our report dated March 10, 2006
expressed an unqualified opinion thereon.

Ernst & Young LLP
Tulsa, Oklahoma
March 10, 2006