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43°30′N91°00′W / 43.5°N 91°W /43.5; -91
TheDriftless Area, also known asBluff Country and thePaleozoic Plateau, is a topographic and cultural region in theMidwestern United States[1] that comprises southwesternWisconsin, southeasternMinnesota, northeasternIowa, and the extreme northwestern corner ofIllinois. The Driftless Area is aUSDA Level III Ecoregion: Ecoregion 52. The Driftless Area takes up a large portion of theUpper Midwest forest–savanna transition. The eastern section of the Driftless Area in Minnesota is called theBlufflands, due to the steep bluffs and cliffs around the river valleys. The western half is known as the Rochester Plateau, which is flatter than the Blufflands.[2] TheCoulee Region is the southwestern part of the Driftless Area in Wisconsin. It is named for the lack of glacial drift in the area: the silt, gravel, and rock left behind by glaciers that can be found in other parts of Wisconsin.[3]
The Driftless Area was never covered by ice during theLast Glacial Period, so the area lacks the characteristic glacial deposits known asdrift. Its landscape is characterized by steep hills, forested ridges, deeply carved river valleys, andkarst geology with spring-fed waterfalls and cold-water trout streams. Ecologically, the Driftless Area's flora and fauna are more closely related to those of theGreat Lakes region andNew England than those of the broader Midwest and centralPlains regions. The steep riverine landscape of both the Driftless Area proper and the surrounding Driftless-like region is the result of early glacial advances that forced preglacial rivers, which flowed into the Great Lakes, southward, causing them to carve a gorge across bedrockcuestas,[1] thereby forming the modern incised upperMississippi River valley.[4][5] The region has elevations ranging from 603 to 1,719 feet (184 to 524 m) atBlue Mound State Park, and together with the Driftless-like region, covers 24,000 square miles (62,200 km2).[6]
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Retreating glaciers leave behind material calleddrift composed of silt, clay, sand, gravel, and boulders. Glacial drift includes unsorted material calledtill and layers deposited by meltwater streams calledoutwash.[7] While drift from early (pre-Illinoian) glaciations has been found in some parts of the region,[8][9][10] much of the incised Paleozoic Plateau of Wisconsin and northwestern Illinois has no evidence of glaciation.
Numerous glacial advances throughout the world occurred during the most recentQuaternary glaciation (also known as the Pleistocene glaciation). TheUpper Midwest andGreat Lakes region ofNorth America was repeatedly covered by advancing and retreating glaciers throughout this period. The Driftless Area escaped much of the scouring and depositional action by the continental glaciers that occurred during the Last Glacial Period, which produced significant differences in thetopography and drainage patterns within the unglaciated area compared to adjacent glaciated regions.
The region has been subjected to large floods from the meltingLaurentide ice sheet and subsequent catastrophic discharges from itsproglacial lakes, such asGlacial Lake Wisconsin,Glacial Lake Agassiz,Glacial Lake Grantsburg, andGlacial Lake Duluth.
The last phases of theWisconsin glaciation involved several major lobes of the Laurentide Ice Sheet: the Des Moines lobe, which flowed down towardDes Moines on the west; the Superior lobe and its sublobes on the north; and the Green Bay lobe and Lake Michigan lobes on the east.[11] The northern and eastern lobes were in part diverted around the area by the Watersmeet Dome, an ancient uplifted area ofCambrian rock underlain bybasalt in northernWisconsin and westernupper Michigan. The southward movement of the continental glacier was also hindered by the great depths of theLake Superior basin and the adjacent highlands of theBayfield Peninsula,Gogebic Range,Porcupine Mountains,Keweenaw Peninsula, and theHuron Mountains along the north rim of theSuperior Upland bordering Lake Superior. The Green Bay and Lake Michigan lobes were also partially blocked by the bedrock of theDoor Peninsula, which presently separatesGreen Bay fromLake Michigan.[11]
Another factor that may have contributed to the lack of glaciation of the Driftless Area is the fractured, permeable bedrock within the Paleozoic Plateau underlying it, which would have promoted below-ground drainage of subglacial water that would otherwise have lubricated the underside of the glacial ice sheet. The dewatering of the underside of the ice sheet would have inhibited forward movement of the glacier into the Driftless Area, especially from the west.
In the adjacent glaciated regions, the glacial retreat left behind drift, which buried all earlier topographical features. Surface water was forced to carve out new stream beds.[12] This process was absent in the Driftless Area, where the originaldrainage systems persisted during and after the Last Glacial Period. Water erosion continued carving the existinggullies,ravines, stream beds, and river valleys ever deeper into the paleozoic plateau, following the original drainage patterns.
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Overall, the region is characterized by an erodedplateau, with bedrock overlain by varying thicknesses ofloess. Most characteristically, the branching river valleys are deeply dissected. The bluffs lining this reach of the Mississippi River climb to nearly 600 feet (180 m). In Minnesota, pre-Illinoian-age till was probably removed by natural means before the deposition of loess. The valley walls' sedimentary rocks date to thePaleozoic Era and are often covered withcolluvium or loess.[13]Bedrock, where not directly exposed, is very near the surface and is composed of "primarilyOrdoviciandolomite,limestone, andsandstone in Minnesota, withCambrian sandstone,shale, and dolomite exposed along the valley walls of the Mississippi River."[13] In the east, theBaraboo Range, an ancient, profoundly erodedmonadnock in south centralWisconsin, consists primarily ofPrecambrianquartzite andrhyolite. The area has not undergone much tectonic action, as all the visible layers of sedimentary rock are approximately horizontal.
Karst topography is found throughout the Driftless area. This is characterized bycaves and cave systems,disappearing streams,blind valleys,underground streams,sinkholes,springs, and cold streams. Disappearing streams occur where surface waters sink down into the earth through fractured bedrock or a sinkhole, either joining anaquifer, or becoming an underground stream. Blind valleys are formed by disappearing streams and lack an outlet to any other stream. Sinkholes result from the collapse of a cave's roof, and surface water can flow directly into them. Disappearing streams can re-emerge as large, cold springs. Cold streams with cold springs as their sources are superbtrout habitat. Due to the rapid movement of underground water through regions with karst topography,groundwater contamination is a major concern in the Driftless area.
The Mississippi River passes through the Driftless Area between and includingPool 2 andPool 13.
As rivers and streams approach their confluence with the Mississippi, their canyons grow progressively steeper and deeper, particularly in the last 25 miles (40 km) in their journey to their mouths. The change in elevation above sea level from ridgetops lining a stream to its confluence with the main-stem Mississippi can reach well past 650 feet (200 m) in only a few miles. TheWaukon Municipal Airport is reliably established as being 1,281 feet (390 m) above sea level.[14] TheArmy Corps of Engineers maintains a river level inPool 9 of about 619 feet (189 m) above sea level,[15] which coversLansing. Maps and signs issued by theIowa Department of Transportation indicate Waukon and Lansing are 17 miles (27 km) apart onIowa Highway 9. This is a drop of more than 660 feet (200 m) in less than 20 miles (32 km) (and this along avery minor tributary of the Mississippi). "The role ofisostatic rebound on the process of stream incision in the area is not clearly understood."[16]
There are many small towns in the Driftless Area, especially in river valleys, at or upstream from the Mississippi. Small towns in a deep steep valley going down to the Mississippi are at risk every 50 to 100 years or so of a major flood, as with the wreck ofGays Mills, Wisconsin, in August 2007, or the holding of the levee inHouston, Minnesota, (on the South ForkRoot River) at the same time. Metropolitan areas have flood walls (See2007 Midwest flooding). In August 2018, the region yet again experienced record-breaking flooding in valley towns such asCoon Valley, Wisconsin,La Farge, Wisconsin andViola, Wisconsin. TheKickapoo River flood stage is 13 feet but was recorded as high as 23 feet during the 2018 flood which was declared a statewide emergency.[17] Many community members were rescued by boats sent by theWisconsin Department of Natural Resources.[18] Days later, when two dams inOntario, Wisconsin broke, it produced flood water downstream inReadstown, Wisconsin,Soldiers Grove, Wisconsin, andGays Mills, Wisconsin.[19]
The history of this portion of theUpper Mississippi River dates back to an origin "as an ice-marginal stream during what had been referred to as the 'Nebraskan glaciation.'" This is an outdated and abandoned period in thePre-Illinoian Stage.[16] The level of erosion often exposesCambrianlimestone of about 510 million years of age.[20] Evidence from soil borings and recentlidar imagery in the lowerWisconsin River valley in the Driftless area suggests that the river in the valley once flowed eastward, rather than its existing westerly course toward its confluence with the Mississippi River. This has led to the hypothesis that the ancient Upper Mississippi River (also named the Wyalusing River) at one time flowed east through the Wisconsin River valley and into theGreat Lakes/Saint Laurence River system somewhere near theDoor Peninsula. The hypothesis posits that the flow of the ancient Wyalusing River was ultimately captured by the ancestral Mississippi River to the south when that river eroded through the Military Ridge nearWyalusing State Park, possibly as a result of an ancient ice sheet in a previous continental glaciation blocking the Wyalusing River to the east. The resultingproglacial lake would have filled the Wyalusing River valley until it overtopped the Military Ridge, ultimately carving through the ridge and draining the lake. This resulted in the ancient Upper Mississippi River changing course and flowing south toward theGulf of Mexico, instead of east into theSaint Lawrence River and the NorthAtlantic Ocean. Thestream capture hypothesis for the Upper Mississippi River would have produced a substantial diversion of water from theGreat Lakes Basin and the Saint Lawrence River, reducing the inflow of fresh water into the North Atlantic with possible impacts toocean currents andclimate.
The Mississippi River trench is one of the few places in the Driftless Area where the bedrock is very deep below the surface, and is overlaid by large amounts of sediment.[21] As home to the formation of a substantial portion of the gorge of the Upper Mississippi, this enormous quantity of sediment goes down at least 300 feet (91 m) under the present riverbottom at the confluence of theWisconsin River.[22] In contrast, as the Mississippi exits the Driftless Area "betweenFulton andMuscatine, [... (Pool 13)], it flows over or near bedrock."[23] "The course of the upper Mississippi River along the margin of the Driftless Area of southeastern Minnesota is believed to have been established during pre-Wisconsin time, when a glacial advance from the west displaced the river eastward from central Iowa to its present position."[24]
Other rivers affected by this geologic process are:
Although lying just to the north of the Driftless Area, theSaint Croix in Wisconsin and Minnesota is another important river that affected the area, as it was the outlet forGlacial Lake Duluth, forerunner toLake Superior, when the eastern outlet was blocked by the continental ice sheet. All major rivers in and adjacent to the Driftless Area have deep, dramatic canyons giving testimony to the immense quantity of water which once surged through them as a result of the nearby meltingglaciers associated with the miles-highice sheets during recurringice ages. Other examples include the Wisconsin River, which drainedGlacial Lake Wisconsin, andGlacial River Warren (whose bed is occupied by theMinnesota River), which drained the colossalGlacial Lake Agassiz. There was ample water to dig a very deep, hundreds-of-miles-long gash into the North American bedrock where the Upper Mississippi River now flows.
The climate ishumid continental, displaying both the cool summer and warm summer subtypes as one travels from north to south.[25] TheUnited States Department of Agriculture has the region falling mainly inzone 5a, with the northern fringe being 4b. A few patches in Wisconsin are 4a.
Before European settlement in the 19th century, the vegetation consisted oftallgrass prairie andbur oaksavanna on ridgetops and dry upper slopes,sugar maple-basswood-oak forest on moister slopes, sugar maple-basswood forests in protected valleys and on north-facing slopes, wet prairies along the rivers, and some mesicprairie on the floodplain farther back from the river.[citation needed] There were probably also oak forests that contained no sugar maple. Marsh and floodplain forests were also common on river flood plains. Prairie was restricted primarily to the broader ridgetops, which were unfavorable sites for trees due to thin soils and shallow bedrock, rapid drainage, and desiccating winds; all these conditions were also good for carrying fires across the landscape. Prairies also occurred on steep slopes with south or southwest aspect (seegoat prairie[13]). Natural fire, which has long been vigorously suppressed, was essential for the regeneration of such prairies.
Evidence of ancient extinct ice age animals that once inhabited the Driftless Area has been discovered over the years. An example of extinctPleistocene megafauna in the area is theBoaz mastodon, a composite skeleton of two separatemastodons found in the 1890s in southwesternWisconsin. Although evidence exists that mastodons inhabited mostly coniferousspruce forests associated with thetaigabiome, it is likely that most or all of the Driftless Area was at times covered bytundra andpermafrost during periods ofglacial maximums.
The Midwest Driftless Area Restoration Effort is a multi-agency cooperative effort to restore the landscape.[26] The main issues are erosion and water pollution from agricultural and animal runoff.[citation needed] Many farmers in the region usecontour plowing,strip cropping, and other agricultural practices to reduce soil erosion due to the hilly terrain. Water pollution is critical inkarsted regions such as this because it can degrade or destroy prime cold-water fish habitat. Soil erosion presents theArmy Corps of Engineers with a problem that requires it to dredge the Mississippi River shipping channels to keep them open.Trout Unlimited is part of this effort, if only because of the superb cold-water streams the region supports.[27] A symposium was held in 2007 inDecorah, Iowa, "to share the results of research, management and monitoring work in the Driftless Area."[28] TheNature Conservancy is also interested.
The Driftless Area contains more than half of the world'salgific talus slopes, a type of small, isolated ecosystem.[29] These refugia create cool summer and fall microclimates that host species usually found further north. They contain at least oneendangered species, theIowa Pleistocene Snail, and a threatened plant, theNorthern monkshood.[30] TheDriftless Area National Wildlife Refuge was primarily carved out of theUpper Mississippi River National Wildlife and Fish Refuge to protect these species and their associated ecosystems.
Isolated relic stands of pines and associated northern vegetation are found in some locations wherealgific talus slopes exist. These trees survive in the cooler microclimate at these locations outside of their range further north.
A noteworthy annual event is the rising offishflies, a kind ofmayfly endemic to the Mississippi valley in the region. These are aquatic insects attracted to light, which rise by the millions as adults to mate, only to die within hours.[31]
Wildlife is abundant with opportunities for huntingwhitetail deer andwild turkey. Fishing, particularly forbrown trout,brook trout, andrainbow trout in tributaries, and species such aschannel catfish in the Mississippi is available, withice fishing in winter.[32]
The Driftless Area is part of theMississippi Flyway. Many birds fly over the river in large flocks, going north in spring and south in autumn.
There are very few natural lakes in the region. They are in adjoining areas of glacial till, drift, and in moraines; the region is extraordinarily well drained, and there is rarely a place where even a pond can naturally form. There are also very few dams because the valley walls and floors are very often fissured or crumbly, or very porous, providing poor anchors for a dam and making it difficult to keep any kind of reservoir appropriately filled. There are no realwaterfalls, but some very strong springs bear the name.
A modern, man-made characteristic is the comparatively twisty nature of highways in the region, as inKentucky, in contrast to the usually rigid east-west/north-south alignment elsewhere in the Midwest.[citation needed] Here, the roads switchback up stream valleys or travel over ridge tops.U.S. Highway 20 through the Driftless, and particularly in Illinois, is a good example.
The Driftless Area provides good conditions for growing crops and grazing livestock. In recent years, the region has generated much public interest in the organic and artisanal food market.
Organic dairy and beef production is of particular economic significance to the Driftless.Organic Valley, the largest organic dairy cooperative in the U.S., was founded and is headquartered in La Farge, Wisconsin. The region's cheese production boasts specialty cheeses such as raw-milk artisan cheese made from unpasteurized milk.[33] Organic dairy generally fits best with a grass-based milk production system.[34]
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The bioregion's economic and cultural characteristics were federally recognized with the granting of the Upper Mississippi River Valley (UMRV) viticultural area, the largest designated winemaking region in the country, by the Treasury Division'sTax and Trade Bureau in 2009. The petition for designation maintains that the region is a cohesive whole for marketing wine, and is also used to market other products.[35]
In addition to wine-grape production and wine-making, the region, especially in southeast Minnesota, is known for apple, maple syrup, and honey production. Tobacco was once a key crop of the Driftless, which has suitable topography and sandy, nutrient-rich soil.[36]
The Driftless Region Food and Farm Project, in partnership with theUniversity of Wisconsin-Madison Center for Integrated Agricultural Systems, is a coalition of sustainable-agriculture farmers, processors, distributors, chefs, planning commissions, and other participants. The project seeks to define the culinary identity of the region and further direct the development ofagritourism.[37]
Fine-grained silica sand is typical of the Driftless and is mined for use primarily inhydraulic fracturing, commonly known as "fracking".
The presence ofsandstone bedrock at or near the surface encouragessand mining in the Driftless, with Wisconsin at the industry's forefront.[38] The sandstone containsquartz (silica) sand grains of the ideal hardness, shape, and size for use in hydraulic fracturing by thepetroleum andnatural gas industries. The mining activity involves quarrying the sandstone bedrock by blasting withdynamite, crushing the rock, washing, drying, and grading the resulting sand, and transporting the sand out by barge or train.[39] In 2017, there were 73 frac sand mines in operation in Wisconsin alone,[40] and there are five operating industrial sand mines in Minnesota;[41] the proliferation of sand mines in the region created new jobs and generated economic activity. But the prominence of industry has raised concern about its effect on water quality, air pollution caused by silica dust, noise andlight pollution, heavy truck traffic, and the destruction of hills and ridges for which the region is known.[42] Industry changes as of 2021[update] have caused Hi-Crush,Covia, and Superior Silica Sands—all with operations in Wisconsin—to liquidate their frac sand mines and declare bankruptcy.[43]
Corresponding to thesoutheast geological region of Minnesota, the colloquial "Driftless Area" (though the whole region was glaciated) begins at aboutFort Snelling. Starting as a narrow sliver against the Mississippi, it widens to the west as one goes south. The western boundary is the Bemis-Altamont moraine.[44][45] Another more easily found reference to the western boundary is the approximate line ofMinnesota State Highway 56.
The upland plateau lies west of the incised tributaries to the Mississippi. The historic vegetation was mixed woodland, with occasionalgoat prairies on southwesterly facing slopes.[46] In the western section is "an old plateau covered byloess [...] along the eastern border and pre-Wisconsin age glacialtill in the central and western parts. The western portion is a gently rolling glacial till plain that is covered by loess in places."[45]
The area includes all or part ofDakota,Goodhue,Rice,Wabasha,Winona,Olmsted,Dodge,Houston,Fillmore, andMower Counties. Aside from the southeastern suburban sprawl of theTwin Cities,Rochester is the main urban area. Additional communities includeRed Wing,Lake City,Winona,La Crescent,Chatfield,Lanesboro,Rushford,Houston, andCaledonia.
Glacial River Warren, in whose bed theMinnesota River now flows, entered the "Driftless Area" just downriver from present-dayMinneapolis-Saint Paul, atFort Snelling, overRiver Warren Falls, "an impressive 2700 feet (823 m) across and 175 feet (53 m) tall, over 10 times as wide as Niagara falls"[47] (this has since receded to becomeSaint Anthony Falls). The region is characterized "by the absence of glacial drift deposits, the sculpted topography, and the presence of the ancient limestone immediately beneath the soil and in cliff outcroppings."[48] The Minnesota Driftless Area did not reach the Twin Cities or any areas to the north or west of them; rather, the Twin Cities marked the edge of glaciation, with substantialterminal moraines overlying the region.[49]
The largest protected area isRichard J. Dorer Memorial Hardwood State Forest, which contains some state-owned land, but is mostly private, controlled by state conservation easements.
Around 85% of the Driftless Area lies within Wisconsin, comprising much of the southwestern quarter of the state. The border is defined by the catchment of theChippewa River on the north, and somewhat west (or east, depending on if the southwestern portion of Wisconsin'sCentral Plain is included) of the north-south line of theWisconsin River. Where the Wisconsin River turns west to join the Mississippi, the area to the south, including the whole ofGrant County as well as most ofLafayette County, are part of the Driftless Area.
The rugged terrain comprising most of the Driftless Area is distinct from the rest of Wisconsin, and is known locally as theCoulee Region. The steep ridges, numerous rock outcroppings, and deep, narrow valleys in the Driftless Area are in marked contrast with the rest of the state, where glaciers have modified the landscape. The hilly unglaciated landscape is well represented in Wisconsin'sCoulee Experimental State Forest,Wildcat Mountain State Park,Governor Dodge State Park,Perrot State Park, and the Kickapoo Valley Reserve.
Karst topography is most prominent in Wisconsin.Eagle Cave inBlue River, WI andCave of the Mounds, nearBlue Mounds, WI, are better known examples.
The Driftless Area is located in all or part ofPierce,Pepin,Dunn,Eau Claire,Buffalo,Trempealeau,Jackson,La Crosse,Monroe,Juneau,Vernon,Richland,Sauk,Crawford,Iowa,Dane,Green,Grant, andLafayette counties. If the less restrictive definition of the Driftless Area is used (which includes the unglaciated southwestern portion of Wisconsin'sCentral Plain), thenAdams and portions of southernWood andPortage counties are also included.La Crosse is the principal urban area wholly within the Driftless Area, while the largerMadison's far western suburbs are located on the edges of the area. Small cities and towns are scattered throughout the region. NumerousAmish settlements are also located within Wisconsin's Driftless Area.
The U.S. Army maintains a presence atFort McCoy inMonroe County betweenSparta andTomah, immediately south of theBlack River State Forest. The property is used mainly for military training exercises, although troops have also been based there for deployments overseas.
The Coulee Region portion of the Driftless Area comprises much of Wisconsin'sWestern Upland geographical region. The most rugged part of Wisconsin's Driftless area is also called theOcooch Mountains.
Largely rural in character, land cover is forest, farmland, and grassland/pasture; modest wetlands are found in river valleys, and along the Mississippi.[50] Row crop farming is less encountered than elsewhere in the state.[51] Away from the Mississippi, Wisconsin, and other major rivers, much of the terrain is gently rolling, supporting dairy farms. In other areas, the rugged nature of the topography in the region is not conducive to farming, except on ridge tops and in river valleys. The sides of the ridges are often too steep for farming, and are usually forested. TheCoulee Experimental State Forest nearLa Crosse was created in part to testsoil conservation practices to prevent soil erosion in the hilly Driftless Area.
The northeastern portion of the Driftless area was covered by or bordered byGlacial Lake Wisconsin during theWisconsin glaciation. The steep-sided rocky bluffs present inRoche-a-Cri State Park andMill Bluff State Park areCambrian outliers of the Franconiacuesta to the southwest and were once islands orsea stacks in the ancient lake. The flat plain in which these bluffs lie is located in the southwest portion of Wisconsin'sCentral Plain geographic region, and was formed in part by sediments falling to the bottom ofGlacial Lake Wisconsin. This flat plain consists of sandy deposits and contains manybogs that were left over from Glacial Lake Wisconsin. Many of these bogs have been converted intocranberry marshes, helping to make Wisconsin a leader in cranberry production. The remainder of the sand plain consists of forest and irrigated farmland. TheDells of the Wisconsin River were carved through the bedrock during the sudden draining of Glacial Lake Wisconsin at the end of the lastice age.
Due to the lack of natural lakes in theCoulee region, several large artificial lakes have been constructed for flood control and recreational purposes, includingDutch Hollow Lake andLake Redstone in Sauk County, Blackhawk Lake in Iowa County, and Yellowstone Lake (inYellowstone State Park) in Lafayette County. Plans for a largereservoir on theKickapoo River atLa Farge, Wisconsin were dropped in 1975 after much controversy due to cost-benefit and environmental concerns. Land previously acquired for the reservoir became the Kickapoo Valley Reserve, an 8,569 acre public forest and wildlife area.
Wazee Lake, at 355 feet (108 m) deep, is Wisconsin's deepest inland lake, and is located in Jackson County in the northeast portion of the Driftless Area. The artificial lake lies in the former open pit Jackson County Iron Mine and is the centerpiece of the Wazee Lake Recreation Area. Due to its great depth, vertical underwater cliffs, clear water, and submerged mining features, the lake is popular withscuba divers.
The highest point in the Driftless area is West Blue Mound, with an elevation of 1,719 feet (524 m).[52][53] The feature is located inBlue Mound State Park, in Iowa County.
During the 19th and early 20th centuries,lead andzinc mining was a major industrial activity in the Driftless Area, drawing many foreign immigrants to settle in the region to work in the mines. Early miners often lived in the mine tunnels, leading outsiders to compare them to the burrowingbadger, a nickname that eventually came to be used for all Wisconsin residents. An example of an early leadshot tower and smelting house is preserved inTower Hill State Park.
Due to the influx of early miners, the lead mining region became Wisconsin's most populous area at the time. The first capitol of theWisconsin Territory was located for a short time atBelmont, Lafayette County in the heart of the lead mining region. The site of the first capitol is preserved at theFirst Capitol Historic Site.
Three units of theIce Age National Scientific Reserve are located within or adjacent to the Driftless Area:Devil's Lake State Park,Mill Bluff State Park, and Cross Plains State Park. In addition, theIce Age Trail follows theTerminal moraine of the maximum glacial extent from the last ice age and enters the Driftless Area in several locations.
Other notable natural features include theBaraboo Range (consisting of two heavily forested, steep, rockyquartzite ridges with mountain-type scenery), rock formations inNatural Bridge State Park (Wisconsin), the forested bluffs, floodplains, islands, and sandbars in the Lower Wisconsin River State Riverway, the confluence of theWisconsin River with the Mississippi River atWyalusing State Park,Trempealeau Mountain State Natural Area in theMississippi River valley atPerrot State Park, and the gorge and rock formations surrounding the Wisconsin River at theDells of the Wisconsin River. TheBlack River State Forest protects a large area of theNorth Woods, rocky bluffs, sandy plains, and river shoreline on the northeastern edge of the Driftless Area that provides habitat for severalwolf packs and one of Wisconsin's reintroducedelk herds.
An area in northeast Iowa that shares similar topographic characteristics to the Driftless Area in southeastern Wisconsin is the Paleozoic Plateau.[54] For counties inland from the Mississippi, evidence is largely confined to the valleys of streams and rivers. It encompasses all ofAllamakee, and part ofClayton,Fayette,Delaware,Winneshiek,Howard,Dubuque, andJackson Counties.Dubuque is the only metropolitan area.
The region is distinct from the "Iowan Erosion Surface to the west and the Southern Iowa Drift Plain to the south."[16] A line east of the most easterly tributaries of theWapsipinicon River defines the western boundary of the landform region, with the catchment of theMaquoketa River south ofBellevue serving as a southern boundary. The most western tributaries of theUpper Iowa,Yellow, andTurkey Rivers flow east and south from the vicinity of this moraine.
Outside ofDubuque, this region of Iowa is thinly populated. In the western section, agriculture and livestock raising are the norm. As one travels east, and as the valleys tumble down to the Mississippi, much of the land is virtually wild, with a great deal of it publicly owned. The state maintains an extensive number of wildlife management areas, along with state forests and state parks.
The most impressive area is on the Mississippi, betweenPikes Peak State Park, opposite the Wisconsin River down toGuttenberg, where bluffs lining the river reach their maximum height. This is apparently an Iowa continuation of Military Ridge, a catchment-defining divide in Wisconsin that was used for theMilitary Ridge Road, a portion of which is included inMilitary Ridge State Trail, both across the River in Wisconsin.
Effigy Mounds National Monument is at the heart of a network of adjacent parks, state forests, preserves, as well as national wildlife refuges, all of which preserve and illustrate the features of the Driftless, where "patchy remnants of Pre-Illinoian glacial drift more than 500,000 years old recently have been discovered in the area."[55] Additional protected areas areCold Water Spring State Preserve nearDecorah,Maquoketa Caves State Park northwest ofMaquoketa,Bellevue State Park adjacent toBellevue,White Pine Hollow State Forest (which protects Iowa's only remaining groves of old-growthwhite pine trees) near Dubuque, and theYellow River State Forest in the southeastern corner ofAllamakee County, Iowa.
The Illinois portion of the Driftless Area is confined mainly toJo Daviess County; western parts ofCarroll County (theMississippi River bluffs characteristic of the Driftless terminate aroundSavanna) and a tiny portion of northwestWhiteside County are also included.[57] The region contains the highest points in the state, of which "the most notable areCharles Mound and Benton Mound, rising to heights of 1,246 feet (380 m) and 1,226 feet (374 m) respectively."[58] The region "has many sinkholes and sinkhole ponds."[59]
The valley of theApple River has a major canyon, withApple River Canyon occupying much of it. The mouth of this river, nearHanover adjacent to the former Savanna Army Depot, comes close to the southern end of the Driftless Area on the eastern side of the Mississippi (seeLock and Dam No. 13).[citation needed]
As in Wisconsin, the Illinois portion of the driftless area was a major early center forlead andzinc mining.[citation needed]
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