Watch out for tarantulas, they’re everywhere! You might also see roadrunners, desert cottontails, black-tailed jack rabbits, Gambel’s Quail and various reptilian mongrels. What you probably won’t run into are the borrego, the park has the largest population of Peninsular Bighorn Sheep in the U.S. (nearly 200). However, in a recent three-year period, Mountain Lions were documented taking over 40 radio-collared Bighorn Sheep in Anza-Borrego.