Camp Three Lake features a unique silver maple floodplain forest along a meandering portion of the Peshtigo River, a 40-mile long tributary to Green Bay. Other natural communities present are northern mesic, wet-mesic, and wet forest. The floodplain forest is dominated by large, unbranched silver maple (up to 28 inches in diameter) with a characteristic floodplain understory including poison ivy, calico aster, Virginia wild-rye, gray-headed coneflower, blue skullcap, sensitive fern, and stinging nettle. The groundcover is often thick with grasses and sedges. Exposed drying mud with almost no vegetation, both with and without canopy cover, is frequently found. As one moves away from the river, the silver maple is replaced by black ash. The northern mesic forest contains an overstory of sugar maple, basswood, hemlock, and yellow birch. Other trees include paper birch, red maple, and balsam fir. Groundlayer species include northern tree club-moss, wild red raspberry, large-leaved aster, tall blue lettuce, and Pennsylvania sedge. White cedar, black spruce, and tamarack dominate the wet-mesic forest; black spruce and tamarack are common in the northern wet forest canopy. Understory species includes velvet-leaf blueberry, creeping snowberry, bunchberry, and yellow bluebead lily. Camp Three Lake is a deep, soft-water lake surrounded by open bog, hemlock slopes, hardwood forest, and white pine. The lake has sparse aquatic vegetation, although an emergent aquatic community occurs to the north. Two creeks draining into the Peshtigo River are included within the site. Haymeadow Creek features abundant northern sedge meadow community with some alder thicket. Whiting Creek passes through mixed conifer swamp before joining the Peshtigo. Breeding bird species include pileated woodpecker, least flycatcher, blue-headed vireo, winter wren, scarlet tanager, and cape may, mourning, magnolia, and black-throated blue warblers. Camp 3 Lake is owned by the US Forest Service and was designated a State Natural Area in 2007.