The majority of the Cuyamaca 100k course lies within the boundaries of Cuyamaca Rancho State Park approximately one hour east of San Diego. The course consists of three distinct loops, all of which start and end at Camp Cuyamaca off of Highway 79. Each loop covers a different set of trails with minimal back tracking and repetition. The first and longest loop of 31.5 miles traverses the western side of the park from south to north and approaches the summit of the park's high point, Cuyamaca Peak, at 6500'. The second loop is 12.6 miles, and takes in the southeast corner of the park near Oakzanita Peak. The final loop of 18.3 miles brings runners through northern section of the park, briefly leaves the park and enters Anza Borrego, and travels along the PCT overlooking spectacular desert views, before returning to Cuyamaca's northern meadows and returning south to the finish.