Northwest Pipeline Corporation. The Group's principal activity is to own and operate an interstate natural gas pipeline system, including facilities for mainline transmission and gas storage. This system extends from the San Juan Basin in northwestern New Mexico and southwestern Colorado through Colorado, Utah, Wyoming, Idaho, Oregon and Washington to a point on the Canadian border near Sumas, Washington. In 2002, the Group transported natural gas for a total of 166 customers. The Group provides services for markets in California, New Mexico, Colorado, Utah, Nevada, Wyoming, Idaho, Oregon and Washington. The Group also provides gas storage services to certain major customers. The Group owns and operates a liquefied natural gas storage facility located near Plymouth, Washington, which provides standby service for the Group's customers during extreme peaks in demand. Gas transportation services accounted for 91% of 2002 revenues and Gas storage services, 9%.