Williams Pipeline Partners L.P. owns and operates natural gas transportation and storage assets. The company owns a 35% general partnership interest in Northwest Pipeline GP, which owns approximately 3,900-mile, bi-directional, interstate natural gas pipeline system from the San Juan Basin in New Mexico, through the Rocky Mountains and to the northwestern United States. Northwest Pipeline GP also has working natural gas storage capacity of approximately 13 billion cubic feet. Williams Pipeline GP LLC serves as the general partner of the company. Williams Pipeline Partners L.P. was founded in 2007 and is based in Tulsa, Oklahoma. As of February 17, 2010, Williams Pipeline Partners L.P. operates as a subsidiary of Williams Partners L.P.