US 97 is a major highway in Washington that spans and consists of mostly two lanes; it is undivided except for the sections that are in urban areas, such as Wenatchee, and concurrencies with I-82 and I-90. The entire route from the Oregon state line to the Canada–US border is part of the National Highway System, a system of roadways classified as important to the nation's economy, defense and mobility. At the southern terminus of the I-82 – US 12 concurrency in Union Gap, US 97 had an estimated daily average of 20,000 motorists in 2007, making it both the busiest segment of the highway in Washington and the fifth busiest segment of U.S. routes in Washington. The busiest segment of US 97 in 1970 was at Main Street in Selah, with a daily average of 17,100 motorists.
