The Mogollon (MUGgy-own) Rim represents the edge of the Colorado plateau to the north, and
terminates at an altitude of around 5000-7000 ft. (map) above sea level. Many of the
rock layers that make up the southern portion of the plateau are exposed here.
The ages of most of these rocks are some lower Mesozoic, mostly Paleozoic with
some disconformities, and in some places pre-Cambrian rocks are also exposed.
Summers enjoy monsoonal precipitation. Precipitation is low in the early winter, increasing in February or March. It then drops off again from April through July. During the monsoon season, rapid daytime heating causes moist air to rise and forms the occasional thunderstorm. The monsoon can continue into mid-September but more commonly ends in late August or early September. With the onset of autumn comes dry conditions and sunny skies. Temperatures begin to cool and conditions remain dry until the first winter storms develop.