Devils Rock-Hosselkus Research Natural Area Establishment Record

The Devils Rock-Hosselkus Research Natural Area occupies the upper Brock Mountain peninsula to the east of Lake Shasta. The area is bisected by a prominent ridge of rugged, resistant gray limestone that stretches in a north to south direction for approximately five miles (8 km). This limestone rises above 3000 ft (914 m) in several locations but is deeply cut by the canyon of Low Pass Creek in the northern portion of the area. The area to the east of the limestone is more gentle topography, underlain primarily by shale, and is dominated by the valleys of Flat and Ripgut creeks. The upper slopes above these small permanent streams are thickly vegetated with California black oak forest, canyon live oak (Quercus chrysolepis) forest and Brewer oak (Quercus garryana var. breweri) scrub, while the lower valleys are dominated by Douglas-fir and lush riparian thickets of dogwood (Cornus sessilis), white alder (Alnus rhombifolia) and other species.