The valley is endorheic, with a small dry lake called Parks Lake, and merges southwest into the north of the San Simon Valley, where the San Simon River has its origins in the flatlands, and surrounding perimeter mountains.

The west-flowing Gila River is forced into a NW-West-SW excursion by the small range of the Black Hills (Greenlee County).

The Whitlock Valley drains south from the range, and merges into the north of the San Simon Valley, where the San Simon River forms a playa, flatland region, then continues northwest to the Gila River.

The east of the valley is bordered by the north region of the Peloncillo Mountains (Cochise County), a north–south stretch, only about 8 mi wide.

The south of the valley forms a water divide to the northeast region of San Simon Creek.