The Cedarburg Bog in Ozaukee County is one of the largest and most outstanding wetlands remaining in southeastern Wisconsin. At 1,656 acres, the Cedarburg Bog State Natural Area is a conifer swamp, the largest example of the least abundant type of wetland in the Milwaukee River Basin.
It offers an ideal location for educating literally thousands of area residents and visitors about the vital role that wetlands play in preserving water quality and species diversity in the Milwaukee River watershed.
It contains large expanses of cedar-tamarack swamp forest, in addition to marshes, shrub carr, swamp hardwoods, and both deep and shallow bog lakes. Its most unusual feature is the presence of a string or “patterned” bog, which consists of stunted cedars and tamaracks alternating with flatter, wetter areas dominated by sedges. String bogs are typically found much further north, and the Cedarburg Bog may be the southernmost string bog in all of North America.
The Bog was designated a State Natural Area in 1952: it was the second property in the state added to this program. It is owned primarily by the Wisconsin Department of Natural Resources and the University of Wisconsin-Milwaukee.
It is part of the Cedar Creek watershed, the most central of the Milwaukee River Basin watersheds, and is the second largest protected wetland complex remaining in the basin. Once part of a large glacial lake, six lakes remain within the bog, all with varying sizes and depths.
The meadow vegetation consists of narrow-leaved sedges, pitcher plant, bogbean, water horsetail, arrow-grass, orchids, and the insectivorous sundew and bladderwort. The rare lady slipper orchid can be found here. A conifer-swamp hardwood forest is adjacent to the bog. There is a very diverse flora and fauna; many that are more common in northern boreal forests and that are at their southern range limit here.
Birds found in coniferous swamps include saw-whet owl, hermit thrush, northern waterthrush, veery, and many species of sparrows and warblers. Mammals that use these swamps include white-tailed deer, red fox, coyote and various small mammals. Amphibians include blue spotted salamander, four-toed salamander, American toad, chorus frog, Cope’s gray tree frog, spring peeper, eastern gray tree frog and wood frog.