This area, while beautiful, can be quite deadly if no one knows about your location. 5 gallons per person kept in the vehicle and at least a half-gallon per person to take along the hike. While snakes hide during the peak of the day, care should be made to avoid underbrush and crevices in the rock where snakes can hide. In the wintertime, snakes are not as big a risk. C. exicaulida can cling to the undersides of rocks, sticks, bark, etc.
Scorpions also come out from their shelters in the evening.
This site should only be visited in late fall, winter, or early spring, as it is direly hot other times of the year. Winter is the best time, as temperatures are most pleasant and snakes and scorpions are much less active. The Ford Explorer I was renting ended up with two flat tires from rock punctures.