These mountains are located to the West of the Tucson
Valley. They form part of the southwestern splendor of the area.
The Tucson Mountains formed approximately 70 million years ago from a single volcano of enormous size. The Tucson Mountain Volcano then became extinct, however the crust of the Tucson region remained quite active. The local landscape has actually been extended due to normal faulting and this occurred approximately 17-30 million years ago.