Southwest Bancorp (OKSB) 10-Q 2007 Q2 Quarterly report

Exhibit 32(b)
18 U.S.C. Section 1350 Certification

I hereby certify pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2003, to the best of my knowledge and belief, that the accompanying Form 10-Q of Southwest Bancorp, Inc. (“Southwest”) for the three month period ended March 31, 2007, fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m or 78o(d)); and that the information contained in this Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of Southwest.

By:	/s/ Kerby CrowellKerby Crowell	May 9, 2007  Date
	Executive Vice President, Chief Financial
	Officer and Secretary
	(Principal Financial Officer)

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