Balance Sheet (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
CURRENT ASSETS:
Cash	$ 128	$ 169
Receivables:
Trade	41,317	42,669
Affiliated companies	1,702	1,441
Advances to affiliate	198,021	171,867
Other	9,441	14,051
Materials and supplies	10,209	10,183
Exchange gas due from others	1,481	3,733
Exchange gas offset	0	201
Prepayments and other	4,669	6,164
Total current assets	266,968	250,478
PROPERTY, PLANT AND EQUIPMENT, at cost	3,315,570	3,306,205
Less-Accumulated depreciation	1,392,203	1,367,632
Total property, plant and equipment, net	1,923,367	1,938,573
OTHER ASSETS:
Deferred charges	1,947	2,110
Regulatory assets	39,047	40,853
Total other assets	40,994	42,963
Total assets	2,231,329	2,232,014
Payables:
Trade	11,164	14,363
Affiliated companies	10,651	11,959
Accrued liabilities:
Taxes, other than income taxes	14,458	11,033
Interest	15,155	4,045
Exchange gas due to others	938	2,252
Exchange gas offset	635	0
Customer advances	3,529	5,573
Other	3,071	3,417
Long-term debt due within one year	174,926	174,837
Total current liabilities	234,527	227,479
LONG-TERM DEBT	518,727	518,583
OTHER NONCURRENT LIABILITIES:
Asset retirement obligations	83,730	82,454
Regulatory liabilities	27,737	26,802
Other	5,914	6,108
Total other noncurrent liabilities	$ 117,381	$ 115,364
CONTINGENT LIABILITIES AND COMMITMENTS (Note 2)
OWNER'S EQUITY:
Owner's capital	$ 1,073,892	$ 1,073,892
Retained earnings	286,789	296,668
Accumulated other comprehensive income	13	28
Total owner's equity	1,360,694	1,370,588
Total liabilities and owner's equity	$ 2,231,329	$ 2,232,014