Kentuck Lake features a unique 0.7 mile long, 10-20 meter wide swale flanked by two narrow, curving sandy ridges that parallel the north shore of Kentuck Lake. Wind and wave action, in concert with the lake's size, shape, orientation and basin morphology, have over the centuries created the unique ridge and swale topography found here. The assemblage of plants found on the swale contains representatives of several natural communities seldom found in such close association. Species normally associated with xeric pine forests or barrens exist here intermingled with species characteristic of open bog, conifer swamp, sedge meadow, and calcareous fen. The inland beach consists of a wet, open sandy-peat swale with scattered small trees of tamarack, jack pine, white pine, paper birch, showy mountain ash, red maple, and winter holly. In open areas are patches of bog species such as sphagnum moss, wire-leaved sedges, and ericaceous shrubs interspersed with patches of bog club moss, sundews, bladderworts, beak-rushes, and sedges. The low ridge adjacent to the lake is densely forested with scattered pines, white spruce, red maple, and balsam fir. To the northeast is a one to two meter high, 10-30 meter wide beach ridge forested with an older-growth forest of white and red pine, hemlock, white spruce, black spruce, balsam fir, yellow birch, and white cedar. Further inland is a larger northern wet forest dominated by black spruce and tamarack with small pockets of white cedar, black ash, and red maple. A dense shrub layer of tag alder, winterberry, and mountain holly is present in the less boggy portions of this wetland. Where a deep carpet of sphagnum moss is present, the shrub layer is composed of ericaceous species including Labrador tea, bog rosemary, and cranberry. Common herbaceous species are cinnamon fern, water arum, and swamp false Solomon's seal. Breeding birds include Nashville warbler, yellow-rumped warbler, yellow-bellied flycatcher, and white-throated sparrow. Kentuck Lake is owned by the US Forest Service and was designated a State Natural Area in 2007.