Adjoining the northern boundary of the Ventana Wilderness, this Bureau of Land Management Wilderness Study Area comprises approximately 675 acres. Also included in this unit are three nearby smaller U.S. Forest Service parcels. Elevations range from about 1,600' along the creeks to 2,600' on the ridgeline of Black Rock Ridge.
The vegetation on the hillsides with southern exposure is predominantly chamise interspersed with buckbrush and manzanita. Expanses of oak woodland are found on the north-facing slopes.
Two perennial streams are located on this unit: Black Rock Creek and South Fork Black Rock Creek. Large pines, oaks and sycamores occur along the riparian corridor of these two creeks. Black Rock Ridge dominates the middle of the unit and separates the two streams.