This area offers a variety of diverse ecosystems, from lowland desert (sporting some of the largest barrel cactus and stands of saguaro the author has seen), to mid altitude grasslands, climbing to forests of pinyon pine, alligator juniper and silverleaf oak.   The ranges also support a wide variety of animal life.  The author has encountered: black bear, javalinas, tarantulas, rattle snakes, hummingbirds, buzzards and hawks.  Unfortunately an effort to reintroduce desert bighorn sheep into the area seems to have failed (like most things,  it is considerably more difficult to undo damage than to cause it).  Fortunately cattle grazing is no longer permitted within NPS controlled boundaries in these areas, as a result the vegetation remains lush and diverse.

Along with the range of altitudes, the hiker can encounter a wide range of temperatures.  Expect much cooler temperatures as you climb into the upper elevations of these ranges and carry extra layers in your pack accordingly.  The mountains surrounding Tucson get considerably more rainfall than those in the Phoenix area.  During the summer monsoon expect daily afternoon thunderstorms.  Carry raingear even if the morning skies appear clear, and plan your hike to avoid exposed peaks and ridges during the afternoon hours.

Additional hikes in an around the Tucson area may be found on Andy Flach's excellent site: Tucson Hikes an Illustrated Guide.