Illinois Natural History Survey - University of Illinois

KARST/CAVE AREA 

Bluffs along the Mississippi River in the Karst/Cave RRA, photo by Mike Jeffords, INHS More than 480 caves occur in Illinois. The caves of the Sinkhole Plain in Monroe and St. Clair counties are the most numerous and interesting in the state. In Illinois, caves are found in areas of major limestone or dolomite outcrops called karsts. A few animals have adapted to the dark, cool and humid environment of the deep caves. Some are both blind and colorless, such as isopods, amphipods, pseudo-scorpions, and springtails.

Map of Site
Land Cover Map of Site

SIZE: 291,305 acres; 455 square miles

LOCATION:Southwestern Illinois along the Mississippi River near St. Louis; Madison, Monroe, Randolph, and St. Clair counties.

The Karst/Cave Area RRA includes Mississippi bottomlands and part of the Ozark plateau. Exceptional features are its limestone bedrock, numerous caves and sinkholes, old growth forest, and unique flora and fauna. The area originally contained large areas of forest, prairie, and wetland.

Of the twelve species of bats that occur in Illinios, nine are called cave bats because they generally hibernate in caves or abandoned mines. A Monroe County cave is one of two known hibernation sites of the federally endangered Indiana bat. Gray bats, also a federally endangered species, are limited in Illinois to southern and west-central parts of the state where there are numerous caves. Two other species, the southeastern bat and Rafinesques's big-eared bat, are endangered in Illinois and are only found in the southernmost part of the state.

LANDCOVER : This RRA is half cropland and one-fourth wooded. It has relatively moderate percentages of upland and bottomland woods. This site ranks second in acreage and seventh in percentage of nonforested wetlands among the 30 RRAs.

NATURAL AREAS : The Karst/Cave RRA has the second highest acreage of Natural Areas. Over nine percent of this large site is covered by Natural Area sites. Of the 27 Natural Areas, seven sites are larger than 1,000 acres. Significant natural features are caves, hill prairies, springs, marshes, herpetological areas, and rookeries.

BIOLOGICALLY SIGNIFICANT STREAMS : Designated BSS streams in this RRA include a short length of the Mississippi River and a tributary to Horse Creek, which total 2.9 miles.

HERITAGE SITES : A moderate number of Heritage sites (92) occurs here. Eight significant communities types occur here along with nine plant species, 18 animal species, and two rookeries. There are 14 cave occurrences.

STATE AND FEDERAL LAND : Horseshoe Lake State Park and Kaskaskia State Fish and Wildlife Area are the only state or federal land in this site.

NATURE PRESERVES : There are four Nature Preserves in this site. High quality terrestrial cave and aquatic cave communities, hill prairies, and old growth forest remnants are important natural features of these preserves.

NATURAL DIVISIONS : Five natural divisions comprise this RRA. Most of the area is Lower Mississippi River Bottomlands (43%), Ozarks (28%), and Southern Till Plain (18%). Over a third of the state's Lower Mississippi River Bottomlands Division and 20% of the Ozark Division occurs in this RRA.

SUMMARY OF SITE CHARACTERISTICS: SIZE, BIOLOGIC RESOURCES, AND PUBLIC LANDS

Total Acreage 291,305
Natural Areas

    Acreage

26,230

    Number

27
Biologically Significant Stream Mileage 2.9
Natural Heritage Sites 92
State Land

    State Parks

1

    State Conservation Areas

0

    State Forests

0

    State Fish & Wildlife Areas

1

    Acreage

3,364

    Percentage of RRA

1.2
Federal Land

    Acreage

0

    Percentage of RRA

0.0

 


 

LANDCOVER

    Acres

    % of RRA

Upland forest 38,763.36 20.37
Bottomland forest 11,214.97 5.89
Wetland- nonforested 5,383.39 2.83
Grassland 24,700.95 12.98
Cropland 99,215.85 52.15
Urban/Built-up 2,155.40 1.13
Water 8,818.51 4.64
Total 190,252.43 99.99

 


 

ILLINOIS NATURAL AREAS INVENTORY SITES

    Acres

Bradley Branch Woods 30
Chalfin Bridge Hill Prairie 220
Chouteau Catchfly Site 2
Columbia Hill Prairie 476
Demint Prairie/Prairie Du Rocher Herpetological Site 483
Dry Run Cave System 3,831
Dupo Prairie 13
Eagle Park Marsh 106
East St. Louis (Alorton) Heron Colony 2
Falling Spring 797
Fogelpole Cave 9,319
Fults Hill Prairie--Kidd Lake Marsh 1,268
Illinois Caverns Cave System 2,747
Madonnaville Cave 480
Miles Prairie 51
Mississippi River -Mudds Landing 1,075
Modoc Northwest Geological Area 3
Monroe City Hill Prairie 104
Potato Hill Hill Prairie 667
Prairie Du Rocher-south 89
Renault Cave System 1,073
Renault Geological Area 77
Renault Herpetological Area 249
Saltpeter Cave Area 27
Stemler Cave Area 2,812
Stemler Cave Woods 177
Sugar Loaf Hill Prairie 53

 


 

BIOLOGICALLY SIGNIFICANT STREAMS

    Miles

Mississippi River, rm 114-119, Randolph Co. 1.9
Tributary to Horse Creek 1.0

 


 

NATURAL HERITAGE CATEGORIES
Communities Occurrences

    Types/Species

    Cave

14 2

    Forest

5 4

    Prairie

11 1

    Primary

4 1
Threatened and Endangered Animals

    Amphibian

2 1

    Bird

17 1

    Fish

1 1

    Mammal

1 1

    Reptile

7 3

    Crustacean

4 2
Threatened and Endangered Plants

    Plant-Dicot

18 8

    Plant-Monocot

2 1
Geological Feature

    Geological Feature

4 1
Other

    Rookery

2 1

 


 

STATE AND FEDERAL LAND
State Parks

    Acres

    Horseshoe Lake

3,040
State Conservation Areas 0
State Forests 0
State Fish and Wildlife Areas

    Kaskaskia

324
Federal Land 0

 


 

ILLINOIS NATURE PRESERVES

    Acres

Armin Krueger Speleological 119
Fogelpole Cave 26
Fults Hill Prairie 427
Stemler Cave Woods 118

 


 

NATURAL DIVISIONS Acres in RRA

    % of RRA

    % of Natural Division

Lower Mississippi R Bottomlands 124,504 43.0 34.7
Ozarks 82,675 28.5 20.4
Southern Till Plain 53,528 18.5 0.7
Middle Mississippi Border 15,275 5.3 1.0
Major Water Bodies 13,813 4.8 1.2



Illinois Natural History Survey

1816 South Oak Street, MC 652
Champaign, IL 61820
217-333-6880
cms@inhs.illinois.edu

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