USGS Home
Contact USGS
Search USGS

Soils are silt loam at the surface, but subsoils are generally calcareous loam (till) or calcareous sand and gravel outwash (Hole and Germain 1994). The loess cap is typically about 2 feet thick.

ELEVATION: 580 to 1,220 feet (177 to 372 m).

AREA: 2,134 square miles (5,530 sq km).

STATES: Wisconsin.

CLIMATE: See subsection.

BEDROCK GEOLOGY: Drift thickness over bedrock is generally 100 to 200 feet (Trotta and Cotter 1973). The predominant bedrock underlying the drift is Silurian dolomite, but there is also Ordovician dolomite along the western edge of the sub-subsection; some limestone, sandstone, and shale are included in both the Silurian and Ordovician bedrocks (Ostrom 1981, Morey et al. 1982).

LANDFORMS: Ground moraine covers most of the sub-subsection, but there are outwash channels and end moraines.

LAKES AND STREAMS: Streams such as the Rock, Crawfish, Beaverdam, and Fox Rivers act as fire barriers within this sub-subsection. Kettle lakes are also common, both on end moraines and in narrow outwash channels.

SOILS: A silt-loam loess cap covers most of the loamy and clayey tills. Soils are typically Alfisols.

PRESETTLEMENT VEGETATION: Uplands supported sugar maple-basswood forest, with varying amounts of red oak, elm, and white ash. White and black oaks were probably also present in the forests. Wetlands were numerous and often provided barriers to fire. Marshes and sedge meadows were common, as were conifer swamps (which were much less common on the prairie, savanna, and oak forest-dominated parts of the subsection). Wetlands were quite extensive in portions of this sub-subsection.

NATURAL DISTURBANCE: Little information is currently available about disturbance in forested portions of the sub-subsection.

PRESENT VEGETATION AND LAND USE: Much of this sub-subsection is intensively farmed, but many of the wetlands remain dominated by native vegetation.

RARE PLANT COMMUNITIES: Patterned peatland, southern mesic forest (sugar maple-beech).

RARE PLANTS: Aster furcatus (forked aster), Solidago caesia (blue-stemmed goldenrod), Lithospermum latifolium (American gromwell), Plantago cordata (heart-leaved plantain).

RARE ANIMALS: Calephelis muticum (swamp metalmark).

NATURAL AREAS: State Natural Areas: Spruce Lake Bog, Sander's Park Hardwoods, Oakfield Ledge, Mayville Ledge Beech-Maple Woods, Neda Mine, VanderBloemen Bog, Cedarburg Beech Woods, Cedarburg Bog, Sapa Spruce Bog, Kurtz Woods (169), Riveredge Creek and Ephemeral Pond (197); The Nature Conservancy Preserves: Zinn Preserve.

PUBLIC LAND MANAGERS:

CONSERVATION CONCERNS: There are major fragmentation and isolation impacts on the native vegetation. Exotic plants are rampant.