A part of the dunal system along Lake Michigan. Photo by Steve Bailey.

May 1, 2023

Northeastern Morainal Natural Division Hosts Post Glacial Relict Species

A blue map of the state of Illinois with the top right section in white. To the top right of the map is a zoomed in section that shows the white area larger and in more detail.
Northeastern Morainal Natural Division. Illustration by Sarah Marjanovic.

Some 15,000 years ago the last glacier, the Wisconsin glacier, began to retreat from what is now parts of Boone, DeKalb, DuPage, Kane, Lake, McHenry, Will and Winnebago counties in northeastern Illinois. As it melted and the climate changed, the glacier left behind some of the state’s rarest landforms and the plant and animal communities that depended upon them. Though many of these features were destroyed by agriculture and development, some remain today, protected by state, county and other public entities in what’s called the Northeastern Morainal Natural Division. This protection gives humans the chance to experience what was in Illinois thousands of years ago. For example, families can walk across kames, cone-shaped mounds of glacial debris, at Glacial Park Conservation Area in McHenry County. They can visit a glacial lake in Lake County where the state-endangered water marigold’s golden bloom floats atop the water. They also can walk along the sandy shores of Illinois Beach State Park to see state-endangered bearberries hugging the shoreline.

“These places essentially are living museums that represent what natural features and species existed in the early history of Illinois,” said Brad Semel, endangered species recovery specialist for the Illinois Department of Natural Resources (IDNR). “They depict what much of the early landscape was able to support prior to human settlement.”

A small fish on a white background. The fish is tan with a black stripe down the length along the top and also down the middle of the fish from the nose to tail.
Blacknose shiner. Photo by Matthew Patterson, USFWS.

“The retreat of the glaciers left both unique physical characteristics in the landscape and unique biological features,” he said. Glaciers left behind huge boulders, gravel and sand as well as big chunks of ice the size of a village that created depressions in the land. As the climate further warmed, the ice melted to form natural lakes, many with deep waters. In other areas, glacial outwash created seeps, fens and springs, with marshes interspersed. The glaciers also created what is now Lake Michigan, with sandy beaches and ravines providing yet another habitat for rare plants and animals.

“With such diverse wetlands, prairie, forest, savanna, a glacial lake and streams, the Northeastern Morainal Natural Division hosts the greatest biodiversity in Illinois,” according to an Illinois Department of Natural Resources publication.

“Many of the plant and animal species found in the Northeastern Morainal Division are species found much farther north,” Semel said. “When the glacier retreated, some of those unique species remained behind in Illinois,” Semel said. “Their counterparts are way up north in Wisconsin.”

To see one of the largest glacial kames in the state, visit Glacial Park on Harts Road in McHenry.

“You can walk to the top of the kame and look right over the Nippersink Valley,” Semel said. “The valley is representative of a river outflow that emerged from the glacier.”

A scattering of trees leaf out in early spring in a grassy area. The trees are against a bright blue sky.
Black oak savanna. Photo by Steve Bailey.

Another place to explore glacial remnants is Moraine Hills State Park, where Lake Defiance, a kettle hole glacial lake, can be seen as well as traversed via kayak and canoe.

Other glacial features within the park include kames, bogs and sedge meadows. Sand and gravel left by glaciers provide habitat for oak savannas.

“Even when you’re in the park, you might be able to hear the nearby mining operations taking advantage of sand and gravel deposits, also representative of glacial history,” Semel said.

A walk along the boardwalk at Lake Defiance within Moraine Hills State Park may reveal rare plants such swamp loosestrife, not to be confused with the invasive, exotic purple loosestrife. Swamp loosestrife provides nectar to bumble bees, swallowtail butterflies and other insects. They, in turn, help pollinate the plant. Duck species including the wood duck and blue-winged teal eat the seed capsules of swamp loosestrife, according to John Hilty, author of the website, “Illinois Wildflowers.”

The glacial lakes found in the Northeastern Morainal Natural Division are cooler than other lakes in the state. As such, they provide habitat for fish such as the blacknose shiner, which is only 2-4 inches long as an adult. This species, and others like it, are endangered in the state. Lake County alone has 10,000 acres of large glacial lakes including Fox Chain, Loon, Deep, Diamond, Bangs, Lake Zurich, Timber, Turner, Little Silver, Long and others, according to the IDNR.

Six blue petals are arranged around a bright yellow center of a small flower on a thin green stem. The flowers are surrounded by green vegetation.
Blue-eyed grass. Photo by Steve Bailey.

Another important part of the division is the sandy beaches along Lake Michigan and associated ravines. The state-endangered bearberry, a low shrub more common in the northern boreal zones of the United States, grows at Illinois Beach State Park. The bearberry serves as the sole host plant for the larvae of the state-endangered hoary elfin, a small butterfly.

“It’s likely that the hoary elfin may struggle to persist as temperatures warm throughout the region and the range of more northern species contracts northward,” Semel said. “When the linkages between native species start to break down, we end up with a more biologically depauperate ecosystem.”

Plants and animals within the Northeastern Morainal Natural Division are not only facing climate change, but also encroachment of invasive species and habitat degradation and alteration.

Semel offered this example: Emergent wetlands that provide habitat for rare wetland birds and plants are being inundated with salt spread on roads in winter. The change in water chemistry has resulted in native broadleaf cattail being displaced by the highly invasive narrowleaf cattail, which has a denser structure and doesn’t provide what native species need to survive.

Humans also need and use these sites for recreation and enjoyment. Many opportunities for birdwatching, canoeing, biking and fishing exist. Waterfowl and deer hunting are also allowed in some state lands including Chain O’ Lakes State Park.

Two shorebirds with black heads and white, gray bodies and orange bills and feet stand on a piece of driftwood on a beach. One of the birds lifts it wings and opens its bill to call.
Common tern. Photo by Steve Bailey.

Managing these landscapes is done in part by seven forest preserve districts, two conservation districts and the Illinois Department of Natural Resources. The state, local governments, nonprofits and volunteers work to remove invasive purple loosestrife from wetlands, Eurasian watermilfoil from glacial lakes and European buckthorn from oak savannas growing within the Northeastern Morainal Natural Division, among many other restoration projects. But these groups don’t own all the rare lands in the region; for example, some glacial lakes are managed by homeowner associations, who can work with conservation experts to learn ways to protect these rare sites. Private groups such as Ducks Unlimited also help. The group donated $100,000 to the McHenry County Conservation Area for restoration of Goose Lake in McHenry County, a morainal wetland site where the state-endangered yellow-headed blackbird breeds. The restoration also will help provide more habitat for some of the duck species hunted in the region.

To protect this rare habitat and the flora and fauna that thrive with northeastern Illinois will require the combined efforts of local, state and federal organizations as well as volunteers and nonprofits, according to Semel.

“We have been entrusted to protect and manage these last remaining vestiges of Illinois’ unique ecologic past,” he said.

Sheryl DeVore writes environment and nature pieces for regional and national publications and has had several books published, including “Birds of Illinois” co-authored with her husband, Steven D. Bailey.

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