Phrynosoma hernandesi
The greater short-horned lizard, Phrynosoma hernandesi, is common throughout Utah inhabiting open area including high mountains. It's full range runs from norther Mexico all the way north into Canada, prefering high altitute habitates at the southern end of its range. They can tolerate much colder temperatures than many other reptile species, burying themselves in loose soil and becoming inactive during cold weather. The greater short-horned lizard gives birth to live young in mid to late summer.
The below list of places are great places to possibly see the greater short horned lizard.
The below links contain further information.