Tucson and its surrounding environs have long been a Mecca of sorts for herpetologists. The reason for this is the density and diversity of the amphibian and reptile populations found here. The Sonoran Desert has provided a wide variety of unusual habitats and conditions, and reptiles and amphibians have evolved and adapted to fill them. The mountain ranges, which are forested islands in that desert, have allowed still other forms to evolve in isolation from each other. This page is an illustrated checklist of the species of reptiles and amphibians found within "the 100 mile circle" - an arbitrarily chosen area radiating 100 miles in all directions from the center of Tucson.

The 100 Mile Circle has been broken down into two sections - the first describes the location - where the circle is, and what habitats it contains. The second section lists (and shows) the reptiles and amphibians that live there. Click on the links below.