Williams' Northwest Pipeline system has changed significantly since its beginnings more than 50 years ago. Like the Western states it serves, Northwest's transmission system has expanded to meet the demands of growth.   Today the pipeline is a primary artery for the transmission of natural gas to the Pacific Northwest and Intermountain Region.

What began as a 1,500-mile pipeline is now an approximately 3,900-mile bi-directional transmission system crossing the states of Washington, Oregon, Idaho, Wyoming, Utah and Colorado. Northwest's bi-directional system provides access to British Columbia, Alberta, Rocky Mountain, and San Juan Basin gas supplies. Northwest has a design capacity of 2.9 billion cubic feet per day and delivers 737 billion cubic feet annually.