Balance Sheet (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash	$ 0	$ 0
Receivables:
Trade	38,172	42,702
Affiliated companies	1,505	1,321
Advances to affiliate	123,999	45,137
Other	595	598
Materials and supplies	10,162	10,106
Exchange gas due from others	1,082	3,869
Prepayments and other	6,762	5,740
Total current assets	182,277	109,473
PROPERTY, PLANT AND EQUIPMENT, at cost	3,344,867	3,319,516
Less-Accumulated depreciation	1,462,287	1,424,855
Total property, plant and equipment, net	1,882,580	1,894,661
OTHER ASSETS:
Deferred charges	1,112	2,122
Regulatory assets	31,114	34,900
Total other assets	32,226	37,022
Total assets	2,097,083	2,041,156
Payables:
Trade	13,372	11,243
Affiliated companies	6,607	7,293
Accrued liabilities:
Taxes, other than income taxes	12,719	11,435
Interest	3,593	3,501
Exchange gas due to others	3,181	4,169
Exchange gas offset	1,881	1,428
Customer advances	1,027	1,893
Other	9,968	5,224
Long-term debt due within one year	249,737	184,924
Total current liabilities	302,085	231,110
LONG-TERM DEBT	331,729	334,236
OTHER NONCURRENT LIABILITIES:
Asset retirement obligations	59,880	60,762
Regulatory liabilities	35,367	30,717
Other	3,227	7,316
Total other noncurrent liabilities	98,474	98,795
CONTINGENT LIABILITIES AND COMMITMENTS (Note 2)
OWNER'S EQUITY:
Owner's capital	1,073,892	1,073,892
Retained earnings	290,903	303,123
Total owner's equity	1,364,795	1,377,015
Total liabilities and owner's equity	$ 2,097,083	$ 2,041,156