Thunderhill Raceway Park is a motorsport complex located in northern California, an hour and a half drive away from Sacramento. It is without a doubt the most versatile racing facility in America, having several possible layouts such as 2-mile, 3-mile, and 5-mile road courses, as well as a 315’ x 550’ skidpad and a 662’ x 363’ autocross pad. Thunderhill follows designs planned by Steve Crawford, who envisioned building two independent road courses next to one another: a 2.87 miles East track and a West track with 1.99 miles. The 5-mile combination of both racetracks forms the longest road course in the United States.
Thunderhill East started operations in 1993, adding the West course in 1995. The East track takes advantage of the natural elevation changes in the field, having 15 exhilarating turns where drivers often lose sight of what is coming right ahead of them. The straight segments are ample and long enough to allow easy passing between drivers. Thunderhill West is more technical, requiring top driving skills to leverage momentum while taking its ten turns, which come in quick succession. The 25 Hours of Thunderhill, the most famous event of the circuit and longest endurance racing competition in America, takes place on the combined 5-mile road course since 2003.
Another layout for racing in the combined circuit of Thunderhill is the 5-mile trajectory with double bypass. It takes the alternative road for The Cyclone and follows the West Bypass to provide a simplified driving experience of the racetrack. Interestingly enough, the average speeds and lap times are slower than in the variation including the Cyclone, with 86 mph and 3:29.283.