Here's a nice track that takes the dirt from Ajo Way (just west of Tucson) down to Arivaca, AZ. The route skirts the western edge of the Sieritas. The return trip was via pavement on Sasabe Road. Nice ride consisting of smooth ranch road, some rough ranch road, a short distance of deep, sandy wash, some rocky hill-climbs and descents. Based on the RawHyde Adventure camp's rating system, it's a "3" in difficulty.