Located on the south shore of the Brule River, Brule River Cliffs contains a series of shaded, north-facing cliffs and talus slopes -- a dolomitic outcropping of the Saunders Formation -- with mosses, liverworts, and ferns as prominent members of the cliff flora. The 10 meter high cliffs and associated ravines are cold, wet, and shaded which is prime habitat for two rare fern species. The cliffs also support many other ferns such as walking, bulblet, oak, common polypody, and long beech fern. A rich northern mesic forest covers the slopes above and below the cliffs containing both deciduous and coniferous trees. Dominant species include sugar maple, yellow birch, paper birch, white cedar, and aspen. Dense shrub thickets occur at the outcrop base with mountain maple especially prevalent. Characteristic understory plants include wild sarsaparilla, big-leaved aster, yellow bluebead-lily, and blue cohosh. Birds include winter wren, eastern phoebe, rough-winged swallow, eastern pewee, and ovenbird. Brule River Cliffs is owned by the USDA Forest Service and was designated a State Natural Area in 1996.