Basis of Presentation

9 Months Ended

Sep. 30, 2012

Basis of Presentation [Abstract]

BASIS OF PRESENTATION

1. BASIS OF PRESENTATION

In this report, Northwest Pipeline GP (Northwest) is at times referred to in the first person as “we”, “us” or “our.”

Northwest is indirectly owned by Williams Partners L.P. (WPZ), a publicly traded Delaware limited partnership, which is consolidated by The Williams Companies, Inc. (Williams). As of September 30, 2012, Williams holds an approximate 66 percent interest in WPZ, comprised of an approximate 64 percent limited partner interest and all of WPZ's 2 percent general partner interest.

General

       The accompanying interim financial statements do not include all the notes in our annual financial statements, and therefore, should be read in conjunction with the financial statements and notes thereto in our 2011 Annual Report on Form 10-K. The accompanying unaudited financial statements include all adjustments both normal recurring and others which, in the opinion of our management, are necessary to present fairly our interim financial statements.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.

Certain reclassifications from General and administrative to Operation and maintenance, related to certain employee related expenses of $0.8 million and $2.3 million for the three and nine months endedSeptember 30, 2011, respectively, have been made to conform to the presentation utilized in the 2012 Statement of Comprehensive Income.