<ARTICLE> 5
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REGISTRANT'S REPORT ON FORM 10-Q FOR THE SIX-MONTH PERIOD ENDED JUNE 30, 1999
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>

                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               JUN-30-1999
<CASH>                                       1,496,224
<SECURITIES>                                         0
<RECEIVABLES>                               15,857,766
<ALLOWANCES>                                   171,176
<INVENTORY>                                    299,320
<CURRENT-ASSETS>                            21,843,732
<PP&E>                                     135,948,708
<DEPRECIATION>                              38,066,365
<TOTAL-ASSETS>                             120,031,639
<CURRENT-LIABILITIES>                       17,088,742
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        93,675
<OTHER-SE>                                  66,532,980
<TOTAL-LIABILITY-AND-EQUITY>               120,031,639
<SALES>                                     74,316,950
<TOTAL-REVENUES>                            74,316,950
<CGS>                                                0
<TOTAL-COSTS>                               65,893,882
<OTHER-EXPENSES>                               595,896
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                             651,348
<INCOME-PRETAX>                              7,827,172
<INCOME-TAX>                                 3,068,252
<INCOME-CONTINUING>                                  0
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                 4,758,920
<EPS-BASIC>                                       0.51
<EPS-DILUTED>                                     0.51