November 1, 2021

Virgin Forests, Gigantic Trees, and Special Species; The Wabash Border Natural Division

Photos by the author.

A sunlight dapples on the floor of a lush green forest. Blue sky peeks through the canopy up above.

The Wabash Border Natural Division and its unique and quite different critical natural features are studies in contrast. A primeval virgin old-growth forests with trees towering so high that binoculars are often needed to clearly see the leaves. In addition, endangered mussels, Illinois only National Wild and Scenic River, fish, and herptile species that are found nowhere else in the state are just some of the wonders and treasures found in the Wabash Border Natural Division.

On the surface, gazing at a map of Illinois’ natural divisions, the Wabash Border Natural Division hardly seems inspiring or awe-inducing. Broken down into three sections based on specific floral and faunal communities, within this long, zigged-zagged, oddly bordered natural division lie some of our state’s greatest natural treasures.

A map of the Wabash Border Natural Division that runs along the lower east side of the state of Illinois.

The Wabash Border Natural Division runs along the far eastern side of Illinois, stretching from Vermilion County on the north all the way south to Gallatin County. The western fingers of the Wabash Border division snake along the Wabash’s tributaries into the Southern Till Plain Natural Division, and the eastern edge is defined by the Wabash River itself. No dams exist on this river, contributing significantly to its remarkably diverse fish, herptile and mussel communities. The Wabash River holds the distinction of being the largest undammed river east of the Rocky Mountains.

Equally unique, the Vermilion River, Illinois’ only designated National Wild and Scenic River, resides in this division. In addition, the division contains diverse wetland communities such as marshes, sloughs, floodplains, riverine and riparian habitats, as well as tracts of remnant virgin, climax and old-growth forests. It is those forests, those very trees that are considered by some to be the “jewel in the crown” of the Wabash Border Natural Division.

A graphic with a poem from Robert Ridgeway in 1872 regarding the forests that surround the Wabash River. Surrounding the poem is a photo of a woodland with a waterway from the Wabash area.

When talking with Wade Ulrey, Illinois Department of Natural Resources (IDNR) District Natural Heritage Biologist for the region, it is indeed the trees and the remnants of virgin eastern deciduous forest that first spring to his mind. One of the most notable examples is the renowned Beall Woods Nature Preserve located in Beall Woods State Park. Imagine, if you will, a virgin forest, vast and ancient, that met the early settlers as they crossed the Wabash River on their journey westward. This eastern border of Illinois once was home to the great trees that made up the last stronghold of the eastern deciduous forest. Thankfully, and through conservation efforts, public and private partnerships, and caring individuals, traces of this magnificent and awe-inspiring forest can be found scattered across the areas that border the Wabash and Vermilion rivers.

Three distinct sections exist within the Wabash Border Natural Division – each with its own unique characteristics: Bottomlands, Southern Uplands and Vermilion River.

The Bottomlands Section contains sloughs, marshes and oxbow lakes within the Wabash and Ohio river floodplains and their tributaries. Bottomland forests are the most dominant type of landscape and contain various oak species (swamp white, Shumard and swamp chestnut) combined with sweetgum, silver maple, black willow, tulip poplar, cottonwood and sycamore trees. Within the Bottomlands Section, one can also find examples of wet prairies and marshes which most often are associated with sloughs.

A grassland with a trail mowed through it. In the background are trees and a bright clear blue sky.

The Southern Upland Section is defined by its dry and mesic upland-type forests situated on deep loess bluffs along the Wabash River. These forests are comprised primarily of beech, sweetgum, sugar maple and white oak. The sandstone ravines found in this section provide habitat for some unusual flora and fauna and contain relict species more often found in northern regions, or species limited to the Wabash Border Natural Division itself.

The Vermilion River Section has a more rugged type of topography and is where the climax deciduous beech-maple forest is found. This particular forest type is more common in the northeastern United States, and in Illinois is only found in the extreme eastern and southern regions.

Forests are certainly a dominant feature of this natural division, but Ulrey pointed out that the small, less notable species of herptiles, fish and mussels found only in the Wabash Border Division are equally fascinating and vital in the quest to protect and preserve this unique natural division.

Mussels with fanciful and imaginative names like clubshell, rabbitsfoot, little spectaclecase and purple lilliput are imperiled. The purple lilliput is an Illinois-endangered species; the other mussels are all federally and state endangered. In the case of the rabbitsfoot mussel, the Wabash Border Natural Division is a federally designated critical habitat area for the species.

Against a bright blue sky, trees surround a wetland. There are picnic tables under the trees and a couple docks over the water.

One cannot ignore the Jefferson salamander, found only within the Wabash Border Natural Division. According to the Illinois Natural History Survey website, the Jefferson salamander was “First found in Illinois in 1990 at a single pond in Edgar County. It is now known to occur at several localities in the Wabash Border Natural Division but is still restricted to Clark and Edgar counties.” Today this salamander is an Illinois-threatened species.

Among the unique fishes in the Division is the tiny little bluebreast darter, so named for the blue breast present on males. Adults live in clear streams, preferring areas less than a foot in depth having large boulders and fast riffles; young fish select the same streams but shallower waters and smaller rocks. The bluebreast darter is an Illinois-endangered species because it requires high-quality waters and sufficient stream velocity. Siltation, impoundments and runoff have resulted in population declines.

It is these threatened and endangered species in the Wabash Natural Border Division that are so intertwined with what Heritage Biologist Ulrey identified as likely the most significant management challenge, the war on invasive species.

A fish opens its mouth near the surface of murky greenish, brown water. Bits of debris surround the fish.

On the aquatic front, aquatic invaders, such as Asian carp, are a significant management concern. While we hear the most about the silver and bighead carp and the issues associated with their invasion of Wabash River, the black carp is especially worrisome, as one of its favorite foods is mussels. The black carp is so concerning that IDNR has a “bounty/reward” program for anglers who harvest black carp to better understand its distribution and numbers. With the Wabash Border Natural Division being the home to numerous threatened and endangered mussel species, some with only a few small colonies found only in this division, an influx of black carp could conceivably wipe out the few remaining colonies of endangered or threatened mussels.

Those invasive carp are, however, presenting bowfishing enthusiasts with one of the many recreational opportunities found in this division. Long known for excellent bowfishing opportunities for both the invasive species and non-game native species such as gar, anglers enjoy many good fishing opportunities in the divison, especially those who fancy small stream fishing. Those same waters offer opportunities for kayaking, canoeing, boating, and other types of water-related activities.

Hunters can find ample populations of furbearers, deer, turkey and upland game species along with excellent waterfowl hunting due to the division’s location in the Mississippi Flyway.

The best areas to visit and experience the natural wonders of this division are Beall Woods State Park, Middle Fork State Fish and Wildlife Area, Kickapoo State Recreation Area and various sites located within the Vermilion County Conservation District.

No matter your area of interest or preferred outdoor recreational opportunity, the Wabash Border Natural Division will not disappoint!

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.

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