1958 United States Grand Prix for Sports Cars

It was the fourth and final round of the 1958 USAC Road Racing Championship season, the seventeenth round of the Sports Car Club of America's Pacific Coast Championship, the second running of the Riverside Grand Prix, and the first post-World War II running of the United States Grand Prix.

Chuck Daigh won the race overall, driving one of Lance Reventlow's Scarab-Chevrolets.

The race is also noteworthy in the annals of international racing, as the strong second-place finish by a local driver named Dan Gurney earned him a test drive in a factory Ferrari Formula 1 car, effectively launching the Californian's legendary racing career.

The weather at this event was very warm, even for a desert climate that routinely saw daytime temperatures of 100F plus during the summer.

[1] Even with the global warming that emerged decades after the late 1950s, the maximum temperature of Riverside, California never exceeded 79.2 °F (26.2 °C) for the month of October 2013.