Compared to the rest of Central California, Pinnacles is home to a high diversity of reptiles: eight lizards, fourteen snakes, and one turtle. Species most commonly encountered include the western whiptail, coast horned lizard, western fence lizard, common garter snake, striped racer, gopher snake and western rattlesnake. Some species, such as sharp-tailed snake, are most active in the cool, wet months. Others, such as Gilbert’s skink and alligator lizard, are most likely to be seen as the days begin to warm up in April and May. The striped racer and western whiptail prefer the hottest days. And some, such as the western fence lizard and side-blotched lizard, can be seen during all but the hottest and coldest weeks of the year. Western pond turtles are uncommon and elusive, so consider yourself lucky if you see one here. Another elusive reptile is the desert night lizard. It is said to spend almost its entire life in a single decaying log. However, it is sometimes possible to see one at night near the porch light at the Bear Gulch Visitor Center. It lives in the cracks in the building, making occasional forays out to eat insects attracted by the light.
Although you may be tempted to capture reptiles in order to get a closer look at them, this is prohibited here. Binoculars are a great way to get an up-close look at an animal doing what it naturally does, rather than doing what many reptiles do when captured: biting you, defecating on you, or dropping their tails.
Turning over rocks and logs to look for animals is also prohibited, and for good reason. Even the most careful turning over of a rock or log and returning it to its original position disturbs the habitat and may scare the animal away from a perfectly good home. 200,000 people visit Pinnacles each year. If only one in a thousand people did it, that would be 200 people, meaning that rocks and logs could get turned over just about every weekend. The reptiles living there would likely move farther from the trail. Even if they survived this disruption, people on the trail would be less likely to see them. Instead, if you spend enough time looking, many animals that usually hide under rocks and logs can also be seen out in the open.
Checklist of Reptiles and Amphibians of Pinnacles National Park