Driftless Area: Difference between revisions

The '''Driftless Area''' comprises southwestern [[Wisconsin]] and the extreme northwestern corner of [[Illinois]], within the American [[Midwest]].<ref name="Knox Driftless">{{cite journal|doi=10.1130/2019.2543(01)}}</ref> The was never covered by ice during the [[Last Glacial Period|last ice age]] and is consequently characterized by steep, forested ridges, deeply carved river valleys, and [[karst]] geology characterized by spring-fed waterfalls and cold-water trout streams. Ecologically, the Driftless Area's flora and fauna are more closely related to those of the [[Great Lakes region]] and [[New England]] than those of the broader Midwest and central [[Great Plains|Plains regions]]. Colloquially as well as in definitions of ecoregions, the term is often extended to include the topographically similar and incised ''Paleozoic Plateau'' of southeastern [[Minnesota]] and northeastern [[Iowa]],<ref name="USGS description">[http://www.npwrc.usgs.gov/resource/habitat/rlandscp/sec4.htm "Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin: Section IV. Driftless Area"] {{webarchive|url=https://web.archive.org/web/20080327184708/http://www.npwrc.usgs.gov/resource/habitat/rlandscp/sec4.htm |date=2008-03-27 }}, [[USGS]], Retrieved July 13, 2007; another government site, [http://www.mn.nrcs.usda.gov/news/features04/driftless.html "Driftless Area Initiative"] {{webarchive|url=https://web.archive.org/web/20080328021009/http://www.mn.nrcs.usda.gov/news/features04/driftless.html |date=2008-03-28 }}, [[USDA]], retrieved July 15, 2007, gives {{convert|24103|sqmi|km2}} and {{convert|15425063|acre}}</ref> and may be extended into Wisconsin's [[Central Plain (Wisconsin)|Central Plain]]. The region includes elevations ranging from 603 to 1,719 feet (184 to 524 m) at [[Blue Mound State Park]], and covers {{convert|24,000|sqmi|km2|sigfig=3}}.<ref>U.S. Department of Agriculture Natural Resources Conservation Service. [https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/programs/initiatives/?cid=stelprdb1117519 Driftless Area Landscape Conservation Initiative]. Retrieved August 25, 2017.</ref> The rugged terrain is due both to the lack of glacial deposits, or [[Drift (geology)|drift]], and to the incision of the upper [[Mississippi River]] and its tributaries into [[bedrock]].