About: U.S. Route 99 in California

U.S. Route 99 (US 99) was the main north–south United States Numbered Highway on the West Coast of the United States until 1964, running from Calexico, California, on the Mexican border to Blaine, Washington, on the Canadian border. Known also as the "Golden State Highway" and "The Main Street of California", US 99 was an important route in California throughout much of the 1930s as a route for Dust Bowl immigrant farm workers to traverse the state. It was assigned in 1926 and existed until it was replaced for the most part by Interstate 5 (I-5). A large section in the Central Valley is now State Route 99 (SR 99).