Chiggers were found on Uta stansburiana and on ten other lizard species. A total of 923 (39 percent) of the 2354 examined lizards possessed chiggers. The abundance and seasonal occurrence of the chiggers were determined in a study plot and in the three plant belts of the Monument. Temperature and precipitation influenced the emergence and disappearance of larvae on the hosts. Four chiggers were present during warm weather; and one species was present on hosts in the cool weather.