Wolf Lake: Rarities in the Rough

By Greg Spyreas

With clear waters, rare plants, abundant fish, and the legend of a 100-year-old sturgeon, Wolf Lake defies industrial abuses — and public perception — to hold on to its rich biological heritage.

I NEVER REALIZED HOW MUCH TIME botanists spend in their offices until I became one. So when I was asked to help conduct a survey of rare plants a few summers ago at Chicago’s Wolf Lake, I jumped at the opportunity.

I called my family in the city to arrange a visit while I was in town. “I’m coming up to do some fieldwork,” I enthusiastically explained to my mother.

“Wolf Lake? In Chicago?” she asked.

“Yeah, I’ll be looking for rare plants. It’s one of the state’s best aquatic habitats. Have you ever heard of it?” Just then I heard my father in the background: “What’s he looking for, Mafia?” His voice became inaudible, distracted by Sunday’s Bears game.

“What did he say?” I asked.

“Oh nothing, something about mobsters,” my mom replied. “But don’t listen to him.”

Some quick pre-trip research turned up archival photographs from the turn of the last century. They showed sweeping vistas of vegetation and wildlife, and I was salivating with anticipation. My father, on the other hand, was focused on the area’s shadier past. A Chicago cop, he has a reflexive awareness of even the smallest potential for danger.

Undeterred, I asked another friend what he knew about Wolf Lake. “That’s the lake where the murderers dumped their victim,” he said. He was talking, of course, about the infamous 1924 Leopold and Loeb case argued by Clarence Darrow.

Ugh. My scientific expedition to a hidden blue oasis was being drowned by lurid images of a bygone era. But then again, no one I knew had actually been there.

The Lake That Would Not Die

Wolf Lake straddles the Illinois-Indiana state line where Chicago meets Hammond. Millions crossing the border on the East-West Toll Road (I-90) drive right over it every year without giving it a second thought. Like many North-Siders, I was guilty as a kid of defining the entire south shore of Lake Michigan by what I’d seen out my window at 55 miles per hour: expressways, smokestacks, landfills, and an occasional pit mine. It wasn’t until college, far from Chicago, that I learned about seminal studies conducted on natural areas along Lake Michigan’s southern shores and dunes. Open any introductory ecology textbook and you’ll still find them. Long before they even had a name for the new discipline of ecology, the south side of Chicago was the place where people were studying it.

Half a million visitors explore the 580-acre William W. Powers Conservation Area each year, not to mention the 250-acre Eggers Woods and natural areas on the Indiana shore. Wolf Lake itself comprises 804 acres. As a part of the larger Lake Calumet landscape, it attracts picnickers, birders, boaters, duck hunters, and even windsurfers.

But it is the park’s loyal regulars — the fishermen — who reveal Wolf Lake as one of our aquatic jewels. Visitors pull smallmouth and largemouth bass from the lake, as well as northern pike, bluegill, red-ear sunfish, crappie, bullhead, common carp, walleye, tiger muskie, yellow perch, and an occasional wayward Lake Michigan salmon. While regular stocking boosts populations of sport fish, two rare species, the formerly widespread Iowa darter and the banded killifish, also swim here. Diminutive and visually unremarkable, they would hardly be given a second look by you or me. But the darter and killifish only occur in a handful of lakes that retain native aquatic vegetation and clear water. To ichthyologists (fish biologists), their presence is like a neon sign flashing a very clear message: GOOD. FISHING. HERE.

With enough prompting (and coffee), you can get local anglers to talk about another fish. A 100-year-old lake sturgeon allegedly haunts Wolf Lake’s depths. While no one has produced proof of this “white whale,” it feeds the lake’s mystique.

Wolf Lake can also boast of its designation by the Illinois Environmental Protection Agency as a water body that supports fish safe for human consumption. Considering its history and urban industrial setting, this is a remarkable detail. In his recent book, A Natural History of the Chicago Region, Joel Greenberg sums it up:

“The Calumet area [which surrounds Wolf Lake] has experienced every abuse that a wealthy society can subject to a small surface of the earth except significant radiation exposure and warfare… Concentrated in such a confined and biologically important area, the consequences are apparent. A detailed account of what happened here would fill volumes, and even then it would be incomplete, for much went unrecorded.”

He is not exaggerating, There has been enough abuse to fill a book — literally. At over 100 pages, Industrial Wastes in the Calumet Area, 1868 – 1970: A Historical Geography, describes it in detail. So this begs the question: Despite destructive activities of every kind, how has Wolf Lake survived, while other lakes long ago died? It begins with geology.

A Glacial Specialty

Swollen with glacial meltwaters, ancient Lake Chicago once extended several miles south of Lake Michigan’s current southern shore. When it receded, it left behind a blanket of sands and several depressions, one of which would become Wolf Lake. Before Chicago’s booming expansion, Wolf Lake was one of five shallow lakes, all less than four feet deep, surrounded by marsh, wet prairie, and old beach ridges. The area’s porous soil allowed water to flow easily between the lakes just beneath the ground. Like a hole dug in beach sand that quickly fills with hidden water, Wolf Lake and Lake Michigan were, hydrologically speaking, one and the same.

Another unique geologic feature originates from the limestone underlying the region. Glaciers crushed this rock, creating sand high in calcium and magnesium. These minerals dissolve easily and can concentrate in pockets of groundwater and soil. In addition to hard tap-water, this has left us with a complex of unique calcium-rich habitats circling the Great Lakes in a narrow band. These harbor a distinctive community of calcium-loving species adapted to moist, mineral-rich sands. Some of these species occur nowhere else in the world.

To call Wolf Lake a unique lake is a bit misleading; Illinois only has a handful of natural lakes as it is, so any lake here is unique. Small natural ponds and backwater sloughs created by rivers do commonly occur in the prairie state. But any “lake” south of Chicago technically refers to a man-made reservoir, not a true glacial lake. From a biological perspective, this semantic distinction matters. Natural ponds in the Midwest are typically fed by rainwater runoff or river flooding, so they are often temporary, with shallow, muddy water. This is quite unlike a lake that has been fed by a cool, clear underground aquifer for millennia. For the plants and animals that rely on them, a lake is a lake, and everything else is…well…just a pond.

According to experts, Wolf Lake is actually cleaner than Lake Michigan. Lake Michigan survives overnutrification because its great volume can dilute some inputs. But for a small body like Wolf Lake, there is no dilution solution. So what keeps this lake alive? The answer, at least in part, is us.

Although much of the toxic industrial waste we dumped into the area has been cleaned up, heavy metals, PCBs, and other nasty chemicals do still occur in Wolf Lake’s sediments. However, nearby industrial plants on Lake Michigan draw in some 11 million gallons of water daily for use in cooling and manufacturing. After use, some of this water is cleaned and released into a stream that directly feeds into and eventually empties out of Wolf Lake. Scientists speculate that “the relative health of the lake may be in part due to this substantial daily flushing” without which pollutants might build up.

Another unintentional boon to water clarity has been the now infamous explosion of invasive zebra mussels. Despite the billions of dollars in damage they do, these voracious filter feeders very effectively remove pollutants and suspended algae from the water column, where they eventually end up on the lake bottom in the relatively stable substance known as mussel feces.

A final reason for Wolf Lake’s survival stems from roads and levees. These have effectively cordoned the lake off from some of its urban surroundings and their pollutants, which might otherwise drain into it.

The net effect of this fortuitous hydrology can be startling for a first-time visitor. It was a calm day the first time I walked up to the shore. Not only could I see the bottom of the lake, but I could actually see what all the fishermen were trying to catch. I caught a glimpse of a big striped fish (likely a northern pike) that maneuvered in and out of an aquatic forest. The scene resembled a giant outdoor aquarium.

Searching for Ancient Remains

Like bloodhounds, we (myself and fellow Illinois Natural History Survey botanists Dave Ketzner and Paul Marcum) combed the shore for days, heads down, focused on our quarry. Bloodhounds, though, don’t get interrupted by fishermen sitting on buckets.

“Did you lose a contact lens?” they’d ask.

We’d look up, startled and slightly disoriented. Then after seeing the smokestacks on the distant skyline, we’d remember where we were.

“No, we’re botanists,” we’d answer with a smile and thanks, and then quietly move on.

We had found seven threatened or endangered plants by the end of our brief survey — and not a single mobster. This is simply an astonishing number of rarities for such a small, heavily populated park. And that was only the Illinois side. One flowering plant we found constitutes the only population of its kind in the state. While that plant grew on the shore, most of the rare plants grew submerged, flowering aquatic organisms rooted on the lake bottom, concentrated in sections of the lake that escaped sand dredging and tollway construction in the l950s. These lush green colonies have probably been in their same underwater spots, swaying back and forth with the waves for centuries. Not even mighty Lake Michigan supports such colonies, because its depth limits sunlight to the bottom-rooted plants, and its powerful waves uproot them near the shore. In fact, Wolf Lake is the farthest south that several of these plants exist anywhere in the world. Most normally inhabit cold, clear, Canadian, Minnesotan, and Wisconsin lakes; here in Illinois, they are remnants of both a different time and a different place.

Increasingly, people are appreciating Wolf Lake’s uniqueness. Birders have long known about the 170 species of birds that can be seen here. One hundred and fifty biologists conducted a “BioBlitz” of the area in August 2002 and found more than 2,200 species, including rarities such as the river otter, the state-endangered Franklin’s ground squirrel, and a beetle that is yet unnamed and is probably new to science. In an area less than two square miles, they turned up more than 15 unique species every 10 minutes for 24 hours straight.

But these findings don’t even scratch the surface of past abundance here. As late as 1927, for example, the botanist Dr. Henry Pepoon collected 14 different native willow species in a single day’s stroll around the lake. A person could walk all of Missouri, Minnesota, Iowa, Montana, Wyoming, Colorado, New Mexico, Oklahoma, Nebraska, Kansas, North and South Dakota, and a Canadian province or two and you still wouldn’t see that many native willows. Today, only five remain.

One aquatic plant called stiff pondweed (Potamogeton strictifolius) was first discovered and named as new to science at Wolf Lake early in the last century. It has not been found here since.

At one time, “Spikes of Indian rice…looking like aquatic corn” stretched across acres around the lakeshore. This was Zizania aquatica, the large, dark grain found in expensive wild rice mixes. It, too, is gone.

Of the “Acres and acres of mussel beds” which once flourished along the bottom of Wolf Lake, only two native mussels could be located during the BioBlitz. According to Jeremy Tiemann of the Illinois Natural History Survey, there were shells of several other mussel species at the lake, “…but they were relicts [dead shells] of species long gone from the area.” It is a sad but not uncommon event for biologists to turn up shells of mussels that have gone completely extinct in only a few decades. These are the 20th-century fossils we have created.

Eighty years ago, Donald Culross Peattie described Wolf Lake as one of North America’s preeminent natural areas, “…a famous hunting ground for aquatic wildlife...where the plants form one of the most remarkable assemblages of aquatics in the country…no body of water of equal size can boast such a list.” The lake stubbornly holds on to vestiges of this original diversity. Unlike me, most people won’t visit it to see the rare aquatic plants. But, if this flora can sustain itself for another 100 years, the fish will still be biting too—maybe even that old white sturgeon.

The Association for the Wolf Lake Initiative and the Calumet Stewardship Initiative work to restore the Calumet region.