Balance Sheet (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash	$ 0	$ 0
Receivables:
Trade	41,457	42,702
Affiliated companies	1,536	1,321
Advances to affiliate	69,184	45,137
Other	1,693	598
Materials and supplies	10,137	10,106
Exchange gas due from others	2,295	3,869
Prepayments and other	6,017	5,740
Total current assets	132,319	109,473
PROPERTY, PLANT AND EQUIPMENT, at cost	3,327,908	3,319,516
Less-Accumulated depreciation	1,444,392	1,424,855
Total property, plant and equipment, net	1,883,516	1,894,661
OTHER ASSETS:
Deferred charges	1,235	2,122
Regulatory assets	32,290	34,900
Total other assets	33,525	37,022
Total assets	2,049,360	2,041,156
Payables:
Trade	11,169	11,243
Affiliated companies	4,927	7,293
Accrued liabilities:
Taxes, other than income taxes	14,731	11,435
Interest	11,548	3,501
Exchange gas due to others	1,833	4,169
Exchange gas offset	1,501	1,428
Customer advances	1,369	1,893
Other	5,110	5,224
Long-term debt due within one year	0	184,924
Total current liabilities	52,188	231,110
LONG-TERM DEBT	519,304	334,236
OTHER NONCURRENT LIABILITIES:
Asset retirement obligations	59,478	60,762
Regulatory liabilities	32,632	30,717
Other	7,594	7,316
Total other noncurrent liabilities	99,704	98,795
CONTINGENT LIABILITIES AND COMMITMENTS (Note 2)
OWNER'S EQUITY:
Owner's capital	1,073,892	1,073,892
Retained earnings	304,272	303,123
Total owner's equity	1,378,164	1,377,015
Total liabilities and owner's equity	$ 2,049,360	$ 2,041,156