BioDiversity Inventories for the Hill Prairie – Karst Sinkhole Plain Corridor

Pen DauBach, Clifftop

The Hill Prairie – Karst Sinkhole Plain Corridor in Southwestern Illinois constitutes a unique ecosystem in the state. The 40-mile long corridor, in a portion of St. Clair County, much of Monroe County, and a small area of Randolph County, has been designated a Conservation Opportunity Area (COA) by the Illinois Department of Natural Resources and the U.S. Fish & Wildlife Service, because of the region’s rare natural habitats and wildlife. The corridor is also known as Illinois’ Ozark Natural Division, Northern Section.

Forty percent of Illinois’ 495 acres of remaining loess hill prairie can be found in the corridor, precipitously perched atop the looming cliff face of the Mississippi River bluffs. Thirty percent of the state’s remaining 195 acres of limestone glade, an even rarer habitat, are present in the COA. The corridor contains the largest extent of karst terrane in the state, with more caves and sinkholes than any other region in Illinois. The COA also boasts one of the largest, unfragmented and undeveloped forested blocks in Illinois. At the base of the river bluffs, ancient wetlands host many wildlife species, rarely found elsewhere in Illinois. The corridor sustains 42 threatened or endangered species, 55 species in greatest need of conservation, and 7 endemic, globally-rare species found nowhere else on earth.

An ongoing natural history survey catalogs the bio-diversity of the corridor. Data sets about life forms in the overall corridor can be viewed by clicking on the links, below. Clifftop encourages scientists and amateur naturalists to continue to study the magnificent bio-diversity in the corridor.