Diamond Roof features upland hardwoods, fast rocky creeks, mixed conifer swamp, and lakes and spring ponds. The northern hardwood forest has a diverse assemblage of sugar maple, basswood, and either white ash or yellow birch. Other canopy species include paper birch, black cherry, ironwood, American elm, bitternut hickory, beech, and the uncommon butternut. Three creeks occur in the complex: Sasacat Creek, Nine Mile Creek, and McCaslin Brook that supports a rare fern. The stream canopy contains common sugar maple, basswood, and white ash. Other tree species are balsam fir, yellow birch, black ash, red maple, white cedar, and hemlock. The creeks have an occasional shrub layer, but understory trees are common. Common riparian groundlayer species are lady fern, intermediate wood fern, naked miterwort, twin-leaf miterwort, and bulblet fern. Course woody debris is frequent to occasional within the creeks. Surrounding the creeks are lowland conifer swamps and northern wet-mesic forest dominated by white cedar with black spruce, balsam fir, and yellow birch. Much of the conifer swamp contains abundant understory trees featuring branches that make passage difficult. Additional water resources include McCaslin Spring and Upper and Lower Hiwanka Lakes, both of good, undisturbed, quality. Diamond Roof is owned by the US Forest Service and was designated a State Natural Area in 2007.