The Desert Diamond West Valley Phoenix Grand Prix is a Verizon IndyCar Series race held at the Phoenix International Raceway in Avondale, Arizona. Open wheel racing in the Phoenix area dates back to 1915 on a dirt oval at the Arizona State Fairgrounds. The race was revived in 1950 by the AAA, and then passed to the United States Auto Club in 1956. USAC moved the race to the newly built Phoenix International Raceway in 1964. The race became a CART event in 1979, and joined the Indy Racing League in 1996. It was held continuously through 2005.