Spur Lake is a 113-acre muck-bottomed soft-water drainage lake that supports dense beds of emergent, submergent, and floating-leaved aquatic plants. Wild rice is the dominant emergent species. Other plants include white water-lily, bullhead water-lily, large-leaved pondweed, ribbon-leaf pondweed, common pondweed, common bladderwort, pickerel weed, and soft-stem bulrush. Wetlands including open bog, alder thicket, and black spruce-tamarack-white cedar swamp surround the majority of the lake's shoreline. Along the northeast corner is a small stand of old-growth hemlock hardwoods and a floating bog mat. The outlet stream, Twin Lakes Creek, flows southward, joining the Pelican River, which in turn flows to the Wisconsin River. The lake and surrounding wetlands provide habitat for black ducks, ring-necked ducks, osprey, and common loons. Use by migratory waterfowl is heavy. Native Americans used this area for centuries and there is an old campsite on the lakeshore. Spur Lake is owned by the DNR and was designated a State Natural Area in 2007.