Castle Amusement Park was built by industry legend Bud Hurlbut who got his start in the industry building small trains for parks, many of which are still in operation. He is probably most famous for building the Calico Mine Ride and Timber Mountain Log Ride at Knott's. He used to operate most of the rides at Knott's, and when the Knott family decided to do their own rides, he packed up all his stuff and started Castle Amusement Park in Riverside.