Complex sentence: The only developed recreation site nearby is at Willow Creek Hot Springs, just south of the Whitehorse Ranch, where nearby there are miles of trails designated for four-wheel off-road vehicles.
Split into simpler sentences: The only developed recreation site nearby is at Willow Creek Hot Springs, just south of the Whitehorse Ranch. Near the Whitehorse Ranch, there are miles of trails designated for four-wheel off-road vehicles.