North Fork Silver Creek RNA

North Fork Silver Creek Research Natural Area (RNA) was established to represent diverse shrub species that grow in the western Siskiyou Mountains on non-serpentine, metamorphic bedrock.  Red alder (Alnus rubra) dominates the lower riparian zone but is replaced by coniferous forest in the upper reaches. Port Orford cedar (Cupressus lawsoniana) and Douglas-fir (Pseudotsuga menziesii) dominate the moist draw. Upslope forests are dominated by white fir (Abies concolor) and western hemlock (Tsuga heterophylla) with sporadic patches of red huckleberry (Vaccinium parviflora) and tanoak (Lithocarpus densiflorus). Upper slopes are dominated by Douglas fir, sugar pine (Pinus lambertiana), and ponderosa pine (Pinus ponderosa). Manzanita (Arctostaphylos spp.), golden chinquapin (Chrysolepis chrysophylla), Sadler oak (Quercus sadleriana), Pacific rhododendron (Rhododendron macrophyllum), and salal (Gaultheria shallon) make up the shrub layer.