Summerton Bog

State Natural Area (No. 42)

Location: Marquette County. T15N-R8E, Sections 26, 27, 34, 35. 428 acres.

Access: From the intersection of Highways 51 and D, about 3.5 miles north of Endeavor, go west on D 2 miles, then west on Freedom Road one mile to a parking lot south of the road. Bog access is south through the oldfield.

Description: Situated in a glacial lakebed with muck and peat soils, Summerton Bog is a highly diverse complex of low meadow, bog, fen, tamarack, and shrub communities. Water is at or near the surface year-round in the lowland areas, supplied by precipitation and five large artesian springs. The earliest maps of the area, dating back to the 1830s, show sedge meadow as the predominant vegetation. Located in the southeastern corner is a five-acre glacial till island wooded with red and white oaks. On the western flank of the island is a calcareous fen. Its calcium-rich waters have allowed an unusual assemblage of plants to thrive including typical fen species bluejoint grass, sweet grass, tussock sedge, spring cress, valerian, fringed gentian, and lousewort. Forested communities are mostly dominated by tamarack with a few black spruce. Groundlayer species include sundew, pitcher plant, and cranberries. At the southwestern corner is an area of black ash, basswood, and shagbark hickory. Remaining communities are shrub carr and sedge meadow. Poison sumac is abundant throughout the sedge meadow and tamarack bog. Nesting birds include sandhill crane, bobolink, sedge wren, Nashville warbler, and veery. Of note is the presence of the rare pickerel frog (Rana palustris), a species of special concern in Wisconsin. Prescribed burns and brushing are conducted to maintain sedge meadow and fen community vigor. Summerton Bog is owned by the Wisconsin Chapter of the Nature Conservancy and was designated a State Natural Area in 1966.