From the BLM's Red Cliffs Recreation site, adjacent to Interstate 15 on the eastern edge of the wilderness study area, Cottonwood Canyon's roadless acres stretch westward along the lower ridges of the Pine Valley Mountains to the north. Cottonwood's red Navajo sandstone ridges stand out against the jagged black outcroppings of granite and basalt in the Pine Valleys. These grainy textured Triassic and Jurassic sediments have been sculpted into the usual sinuous curves, ridges, mushrooms, alcoves, and canyons found to the east on the Colorado Plateau. Some Quaternary basalt is exposed along the ridges below the northern mountains, echoing the mountains' igneous origins. According to the BLM survey, nearly 80 percent of the Cottonwood Canyon Wilderness Study Area is rock outcrop, stony colluvial land, and badland.
Vegetation is sparse.
Pinyon-juniper woodlands are scattered at elevations above 4,000 feet. On the northern lands of the Dixie National Forest, low mountain slopes are home to big sagebrush, antelope bitterbrush, Utah serviceberry, and mountain mahogany. But large expanses of slickrock limit such vegetation to less than five percent of the land surface. At lower elevations, blackbrush desert shrub vegetation, with intermittent bursage, Mormon tea, and desert bitterbrush, is the dominant type. Here too plant life is restricted by slickrock and rock outcrops that comprise nearly 90 percent of the surface.