Whetstone Mountains
The Whetstone Mountains reach their high point of 2,350 meters (7,711 feet) on Apache Peak. The basal area is relatively high for the Sky Islands beginning firmly in semi-desert or full grasslands. Watersheds on the eastern side drain into the San Pedro River, while those on the western side feed Cienega Creek and eventually flowing into the Rillito River in the Tucson basin, which with the Santa Cruz River shortly thereafter.