Located on ancient land between the Tortolita and Santa Catalina Mountains north of Tucson, the town of Oro Valley is very much a newcomer, having officially incorporated in 1974. But its earliest families date back to 1100, when the Hohokam established villages in the area. In the 1800s, hardy pioneers used the abundant waters of the nearby Ca?ada del Oro to establish cattle ranches, while the early 1900s brought health seekers to ranch or establish...