<TABLE> <S> <C>


<ARTICLE>                                           UT
<LEGEND>
THIS SCHEDULE  CONTAINS SUMMARY FINANCIAL  INFORMATION  EXTRACTED FROM THE MARCH
31, 1998 FINANCIAL  STATEMENTS OF INTERSTATE ENERGY CORPORATION AND IS QUALIFIED
IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL  STATEMENTS.  CERTAIN ADJUSTMENTS
HAVE BEEN MADE TO THE PRIOR PERIOD AMOUNTS AS PART OF THE RESTATEMENT TO REFLECT
THE POOLING OF INTERESTS TRANSACTION,  AND A CHANGE IN ACCOUNTING METHOD FOR OIL
AND GAS PROPERTIES FROM THE FULL COST METHOD TO THE SUCCESSFUL EFFORTS METHOD.
</LEGEND>
<RESTATED>
<CIK>      0000352541
<NAME>     INTERSTATE ENERGY CORPORATION
<MULTIPLIER>     1,000
       
<S>                             <C>
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                                       DEC-31-1998
<PERIOD-START>                                          JAN-01-1998
<PERIOD-END>                                            MAR-31-1998
<BOOK-VALUE>                                               PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                                 3,071,516
<OTHER-PROPERTY-AND-INVEST>                               1,082,362
<TOTAL-CURRENT-ASSETS>                                      383,214
<TOTAL-DEFERRED-CHARGES>                                    123,062
<OTHER-ASSETS>                                              329,032
<TOTAL-ASSETS>                                            4,989,186
<COMMON>                                                        766
<CAPITAL-SURPLUS-PAID-IN>                                   872,464
<RETAINED-EARNINGS>                                         809,067 <F1>
<TOTAL-COMMON-STOCKHOLDERS-EQ>                            1,682,297
<PREFERRED-MANDATORY>                                        24,298
<PREFERRED>                                                  89,102
<LONG-TERM-DEBT-NET>                                      1,447,432
<SHORT-TERM-NOTES>                                           44,524
<LONG-TERM-NOTES-PAYABLE>                                    56,975
<COMMERCIAL-PAPER-OBLIGATIONS>                               44,300
<LONG-TERM-DEBT-CURRENT-PORT>                                67,532
<PREFERRED-STOCK-CURRENT>                                         0
<CAPITAL-LEASE-OBLIGATIONS>                                  20,729
<LEASES-CURRENT>                                             13,129
<OTHER-ITEMS-CAPITAL-AND-LIAB>                            1,498,868
<TOT-CAPITALIZATION-AND-LIAB>                             4,989,186
<GROSS-OPERATING-REVENUE>                                   556,283
<INCOME-TAX-EXPENSE>                                         17,787 <F2>
<OTHER-OPERATING-EXPENSES>                                  482,403
<TOTAL-OPERATING-EXPENSES>                                  482,403 <F2>
<OPERATING-INCOME-LOSS>                                      73,880
<OTHER-INCOME-NET>                                            5,380
<INCOME-BEFORE-INTEREST-EXPEN>                               79,260
<TOTAL-INTEREST-EXPENSE>                                     30,924
<NET-INCOME>                                                 30,549
<PREFERRED-STOCK-DIVIDENDS>                                   1,674
<EARNINGS-AVAILABLE-FOR-COMM>                                28,875
<COMMON-STOCK-DIVIDENDS>                                     36,580
<TOTAL-INTEREST-ON-BONDS>                                    92,370
<CASH-FLOW-OPERATIONS>                                      182,273
<EPS-PRIMARY>                                                  0.38
<EPS-DILUTED>                                                  0.38
<FN>
<F1> Includes $235,396 of Accumulated Other Comprehensive Income.

<F2> Income tax expense is not included in Operating Expense in the Consolidated
Statements of Income.
</FN>
                                               


</TABLE>