Illinois Department of Natural Resources
February 2022
February 1, 2022
View of bluffs near Godfrey, Illinois. Photo by Gretchen Steele.

The Soaring Middle Mississippi Border Natural Division

By Gretchen Steele
Two vultures perch on a tree branch. In the background is a leafy canopy.
Turkey and black vulture perching on a tree branch. Photo by Gretchen Steele.

Soaring. If pressed to describe the Middle Mississippi Border Natural Division in one word, soaring is what immediately comes to my mind. The bluffs, crags and cliffs that soar upwards from the Mississippi floodplain. The bald eagles and turkey vultures that soar and wheel across the sky from perches high up the bluffs and crags. The deep ravines with sides that soar upwards to forest or hill prairie habitat. Soaring views from atop the bluffs that afford us a wide-open look at the Mississippi River and its floodplain below. 

The Middle Mississippi Border Natural Division is a long, narrow strip of bluffs, cliffs, crags and even smaller areas of loess hill prairies and some forest. The division runs all the way from Rock Island County on the north end to St. Clair County and the lower Illinois River floodplain on the southern tip and features two sections within the division—the Glaciated Section and the Driftless Section.

A graphic of a map indicating on the west side of the state of Illinois along the Mississippi River is the Middle Mississippi Border Natural Division.
Middle Mississippi Border Natural Division graphic by Sarah Marjanovic.

Within this awe-inspiring natural division, one is immediately struck by the defining limestone bluffs stretching from the edge of the floodplain ever upwards towards the sky. Worn by wind and water they are studies in cliffs, crags and patterns that invite the imagination to wander. The caves, nooks and crannies scattered throughout lead your eye and mind to wonder about what creatures might be utilizing those sheltering spaces. It is not unusual to see two key species of birds, the bald eagle and the turkey vulture, perched on the outcroppings soaking up the sun or catching a thermal to soar above the river and floodplain as they search for food. In the Driftless Section of the Middle Mississippi Border Natural Division the bluffs are also compromised of sandstone that make intricate patterns and colors easily visible from the roadside. 

As your eye travels up the bluff face one may notice that the drop off from the top bluff line is sharp and steep—a tumble for any hiker that would be a sheer drop to the floodplain below. Yet as one transitions to the glaciated sections of this natural division the drops are not so steep and feature a slope of broken rock and gravel that helps to define the Glaciated Section from the Driftless Section. While less of sheer drop than those found in the Driftless Section, the bluffs are still difficult and somewhat dangerous to navigate on foot. 

Against a bright blue sky is a tan, gray cliff face with small cedar trees growing at the base of the cliff, and at the top of the cliff are grasses interspersed with shrubs.
Photo by Gretchen Steele.

The tops of the bluffs are where the loess hill prairies reside. For Illinois Department of Natural Resources’ District Heritage Biologist Ray Geroff, these ever-shrinking, ever-disappearing hill prairies are the crowning jewels of the Middle Mississippi Border Natural Division. 

“When someone asks about the Middle Mississippi Border Natural Division, I immediately think of the hill prairies,” said Geroff. 

According to the Illinois Department of Natural Resources Education Division, hill prairies are unique habitats that formed on dry, southwest-facing hill tops above the floodplains of rivers, especially the Illinois and Mississippi rivers. Hill prairie soils differ from what we commonly think of as prairie soil as they contain loess (fine-grained, wind-blown soil). They are dry, rocky and arid in many areas, and offer up some of the most unique and unusual species. Most of Illinois’ remaining Illinois hill prairies—there are about 90 sites with good-quality hill prairie habitat—are less than 5 acres in size, and about half of these sites are smaller than 1 acre. Survival of these rare habitats is attributed to the difficultly of accessing the land for agricultural development.

Several notable hill prairie habitats reside within the Middle Mississippi Border Natural Division. Nature preserves dedicated to these unique hill prairies that are open to the public include Grubb Hollow in Pike County and Pere Marquette Nature Preserve, located within Pere Marquette State Park (Jersey County). 

On a partly cloudy day in the summer, a prairie hill-top is partially shaded by the edge of a woodland. In the background is the Mississippi river and the shoreline of Missouri.
View from a bluff at Pere Marquette State Park. Photo by Sarah & Uros Marjanovic.

The loss of hill prairies can be attributed to several factors – early and failed attempts to use the area for agricultural purposes, the encroachment of forest and woodlands with species not normally found in the habitat and, of course, the ever-present threat from invasive species such as bush honeysuckle, Russian olive and the native eastern red cedar. Woodland encroachment and invasive species present the most pressing management challenges to hill prairies. 

The uniqueness of the Middle Mississippi Border Natural Division habitats offers up some of the most rare and unusual species in Illinois, including stick-leaf (Mentzelia oligosperma), prairie larkspur, narrow-leaved milkweed, brassy minnow, slender madtom, banded sculpin, dark-sided salamander and western worm snake. Additional state threatened or endangered species found in the division include the timber rattlesnake, short-eared owl and northern harrier, with both birds present during the winter months. 

Despite the number of threatened and endangered species found in this division, it also provides a good selection of outdoor recreational activities. Deer and turkey hunting, mushroom hunting, camping, hiking and bird watching opportunities are plentiful. 

A gray, rusty, brown timber rattle snake very nearly dissolves into the rocky ground because it is so camouflaged.
Timber Rattler (Crotalus horridus). Photo by Gretchen Steele.

For those wishing to explore the Middle Mississippi Border Natural Division a few publicly accessible areas exist. First and foremost is Pere Marquette State Park, which offers up multiple examples of the habitats found in the division and boasts a staff knowledgeable in the uniqueness of the division. Grubb Hollow Prairie Nature Preserve is publicly accessible but not developed in the usual sense of the word and has few trails. Other areas to consider are the National Great Rivers Museum at Alton Lock and Dam 26, the Lewis and Clark State Historic Site at Hartford, the Center for American Archeological Museum in Kampsville, and the McCulley Heritage Project in Kampsville. 

Perhaps the most enjoyable and easiest way to see and experience the glory of the Middle Mississippi Border Natural Division is to hop in the car and make your way up the Great River Road north from Alton. The scenery, views and small stops along the way make for an excellent weekend getaway to learn more and enjoy this most unique natural division in Illinois.

Gretchen Steele hails from Coulterville, Illinois. Steele is a freelance outdoor communicator. Her award-winning work appears as a regular columnist and contributing feature writer for Heartland Outdoors, Illinois Outdoor News and several Illinois newspapers. She enjoys spending her time afield as a volunteer for the Illinois Department of Natural Resources, Delta Waterfowl Foundation, Retrievers Unlimited and the Illinois Federation of Outdoor Resources. She is currently Vice President of Missouri Outdoor Communicators and a former board member of Association of Great Lakes Outdoor Writers.