One of the best things about Tucson is what's all around it: desert and mountains. It's anything but barren, if you know where to go.
All along the northern edge of the city are the Santa Catalina Mountains, rising to over 9100ft/2770m. Hikers, runners, and birdwatchers find haven here. Bear Canyon, which runs parallel to more popular Sabino Canyon, is a riparian oasis--during the summer monsoon and then during the winter wet season, follow the flowing water to the canyon's end, where Seven Falls cascade over smooth stones...Even when the creek bed is dry, it's a great place for a quiet trail run. (Avoid winter weekends if you're seeking solitude, or just get an early start. Fall through Spring are perfect.)
Wildlife you might see: roadrunners, coyotes, coatimundi, snakes and an abundance of lizards, cottontail rabbits, javelina, deer, bobcats, and yes, mountain lions. (Don't run alone at dawn and dusk.)