<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from the
financial statements filed as part of the Company's 10Q and is qualified in its
entirety by reference to such financial statements.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          MAR-31-1999
<PERIOD-END>                               SEP-30-1998
<CASH>                                          30,241
<SECURITIES>                                         0
<RECEIVABLES>                                  116,251
<ALLOWANCES>                                       203
<INVENTORY>                                          0
<CURRENT-ASSETS>                               159,018
<PP&E>                                         368,437
<DEPRECIATION>                                 160,029
<TOTAL-ASSETS>                                 383,984
<CURRENT-LIABILITIES>                           92,873
<BONDS>                                        100,458
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         6,004
<OTHER-SE>                                     166,852
<TOTAL-LIABILITY-AND-EQUITY>                   383,984
<SALES>                                        208,953
<TOTAL-REVENUES>                               208,953
<CGS>                                          163,934
<TOTAL-COSTS>                                  163,934
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               1,192
<INCOME-PRETAX>                                 23,342
<INCOME-TAX>                                     8,872
<INCOME-CONTINUING>                             14,470
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    14,470
<EPS-PRIMARY>                                      .63
<EPS-DILUTED>                                      .62