Frog Lake and Pines features an undisturbed wilderness lake surrounded by old-growth northern dry-mesic forest in a large lowland bordering the Manitowish River. The 42-acre lake is a deep, soft seepage lake with a dense community of submergent aquatic vegetation including white and yellow pond-lilies, bladworts and spike rushes. Wetlands predominate along the shoreline with bog, sedge meadow, and lowland conifer-hardwood swamp. The bog has an abundance of leather-leaf and Laborador-tea with numerous scattered small trees, sedges, and other ericaceous species. The low conifer-hardwood swamp contains species such as white and black spruce, tamarack, thimbleberry, and three-leaved gold-thread. The remaining shoreline is upland forest consisting primarily of red and white pines some that are more than 2 feet in diameter with other trees including white birch, aspen, red maple, and balsam fir. The understory varies in shrub density from a thicket of hazelnut to a fairly open understory with bracken fern, bunchberry, wild sarsaparilla, American starflower, rough-leaved rice grass, and Canada mayflower. Migrating waterfowl make extensive use of the lake. Frog Lake and Pines is owned by the DNR and was designated a State Natural Area in 1983.