Deansville Fen

State Natural Area (No. 311)

Location: Dane County. T9N-R11E, parts of sections 25, 36. T9N-R12E, parts of sections 30, 31. 604 acres.

Access: From the intersection of State Highways 73 and 19 in Marshall, go west on 19 4.7 miles, then north on Twin Lane Road 3.3 miles, then east on Greenway Road 0.7 mile to a parking area. Walk 0.4-mile east, then south and cross the Maunesha River to the fen.

Description: Located on the western edge of Deansville Marsh Wildlife Area, Deansville Fen is an extensive wetland complex of native plant communities featuring a high quality calcareous fen grading into wet-mesic prairie and sedge meadow. The ground is hummocky and moderately wet with sedges such as tussock sedge, fen star sedge, and cotton grass, numerous grasses including blue-joint grass and big blue-stem, and widely scattered shrubs. The fen contains many rare and unusual plant species that thrive in the carbonate rich soils including grass-of-Parnassus, Kalm's lobelia, valerian, and Riddell's goldenrod. The area also harbors the state-threatened tussock bulrush (Scirpus cespitosus) and two rare plants -- small fringed gentian (Gentianopsis procera) and common bog arrow-grass (Triglochin maritimum). Other plants are fowl manna-grass, marsh marigold, turtlehead, spring-cress, northern bedstraw, swamp lousewort, marsh milkweed, and marsh aster. The wetland is home to a diversity of birds including rare-- short-eared owl (Asio flammeus), which use the area extensively in winter and northern harrier (Circus cyaneus), and bobolink, common snipe, eastern kingbird, sedge wren, and eastern meadowlark. Deansville Fen is owned by the DNR and was designated a State Natural Area in 1996.