Just 22 miles southeast of Tucson in the Sonoran Desert sits the town of Vail, colloquially known as "The Town between the Tracks," which refers to the two train tracks running through its tiny business center. The area is named for Walter L. Vail, who, with his partners, formed the sprawling Empire Ranch in 1876. Vail is also the home of Colossal Cave, a "dry cave" where visitors can view stunning formations and hear stories of Native Americans,...