<TABLE> <S> <C>
<PAGE>
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM SOUTHWEST
BANCORP'S QUARTERLY REPORT ON FORM 10-Q FOR THE QUARTER ENDED MARCH 31, 2000,
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<CASH> 28,295
<INT-BEARING-DEPOSITS> 1,521
<FED-FUNDS-SOLD> 0
<TRADING-ASSETS> 0
<INVESTMENTS-HELD-FOR-SALE> 153,283
<INVESTMENTS-CARRYING> 69,094
<INVESTMENTS-MARKET> 68,143
<LOANS> 903,179
<ALLOWANCE> 11,613
<TOTAL-ASSETS> 1,185,348
<DEPOSITS> 905,492
<SHORT-TERM> 177,850
<LIABILITIES-OTHER> 10,241
<LONG-TERM> 25,013
0
0
<COMMON> 4,081
<OTHER-SE> 62,671
<TOTAL-LIABILITIES-AND-EQUITY> 1,185,348
<INTEREST-LOAN> 39,897
<INTEREST-INVEST> 6,650
<INTEREST-OTHER> 46
<INTEREST-TOTAL> 46,593
<INTEREST-DEPOSIT> 20,901
<INTEREST-EXPENSE> 26,622
<INTEREST-INCOME-NET> 19,971
<LOAN-LOSSES> 1,800
<SECURITIES-GAINS> 0
<EXPENSE-OTHER> 14,724
<INCOME-PRETAX> 7,397
<INCOME-PRE-EXTRAORDINARY> 7,397
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> 4,860
<EPS-BASIC> 1.26
<EPS-DILUTED> 1.25
<YIELD-ACTUAL> 8.46
<LOANS-NON> 12,716
<LOANS-PAST> 81
<LOANS-TROUBLED> 0
<LOANS-PROBLEM> 26,023
<ALLOWANCE-OPEN> 11,190
<CHARGE-OFFS> 1,793
<RECOVERIES> 1,793
<ALLOWANCE-CLOSE> 416
<ALLOWANCE-DOMESTIC> 11,613
<ALLOWANCE-FOREIGN> 11,613
<ALLOWANCE-UNALLOCATED> 1,911
</TABLE>