Castle Rock is home to many reptiles mainly lizards and snakes. Snakes include Gopher Snakes, Western Rattlesnakes and the endangered Alameda Whipsnake among others. Lizards include Western Skinks, Western Fence Lizards, California Whiptails and the Horned Lizard. When Hiking in Castle Rock or the surrounding areas always listen and watch for snakes as they like to lay out in the sun and can often be found on the trails during the day.