Back to Nature at Hennepin and Hopper Lakes

It was an early June morning, the sun had yet to rise and my ears were filled with the buzzing of mosquitos on the edge of the marsh. And then I heard “coo-coo-coo…coo-coo-coo.”

The slow, distinctive call of a least bittern traveled across the marsh at Hennepin and Hopper lakes in Putnam County. In addition to the least bittern, other marsh birds heard that day were the common gallinule and pied-billed grebe.

Hennepin and Hopper lakes are part of the 3,000-acre Sue and Wes Dixon Waterfowl Refuge owned by the Chicago based Wetlands Initiative. Founded in 1994 and dedicated to restoring wetland resources throughout the Midwest, the organization acquired land adjacent to the Illinois River near Hennepin, and since 2001 has been working to restore the area’s hydrology.

Once channels of the Illinois River, Hennepin and Hopper lakes became part of the Hennepin Drainage and Levee District in the early 1900s, allowing the lakes to be drained and the land utilized as farm ground for nearly a hundred years.

In 2001, the Wetlands Initiative began disabling drain tiles and eventually turned off the pump. This landscape level restoration venture is quite large. Standing in the middle of the project area, the sheer size and scale of the place is staggering. A rich diversity of natural communities and habitats are present, including backwater lake, marsh, sedge meadow, wet prairie, mesic prairie, sand prairie and savanna. Previously farmed land was enrolled in the Conservation Reserve Enhancement Program (CREP) and non-farmed acres were protected by conservation easements conveyed to the Marshall-Putnam Soil and Water Conservation District. Most of the site is enrolled in a CREP permanent state conservation easement.

The site supports significant concentrations of birds, some of which breed at the site while others use the site as a stopping point along their migratory route to rest and feed. In 2004, the Audubon Society designated the site as one of the first Important Bird Areas in Illinois. Doug Stotz, an ornithologist at The Field Museum, has documented 276 species of birds at Hennepin and Hopper lakes. Aaron Yetter, an Illinois Natural History Survey waterfowl ecologist, annually counts waterfowl utilizing Hennepin and Hopper lakes. In 2016 the number totaled 2,071,368 birds, down slightly from the 2,308,865 birds documented in 2013. Numbers peak during the March–April and October–November migration periods.Yellow-headed blackbird. Photo by Michael R. Jeffords

Notable state-listed species that breed at the site include king rail, common gallinule, yellow-headed blackbird and least bittern. Barn owls, another state-listed bird species, have been observed nesting in a couple of old barns on the property.

In 2002, a 26-acre portion of the site was dedicated as the Thomas W. and Elizabeth Moews Dore Seep Nature Preserve, an Illinois nature preserve and part of the largest Grade B seep community in the Illinois River Section of the Upper Mississippi River and Illinois River Bottomlands Natural Division. The site also contains a significant diversity of reptiles and amphibians (25 herp species, with 18 known to breed on the site) and is one of the reasons, along with the state-listed bird species breeding at the site, the property was added to the Illinois Natural Areas Inventory (INAI) in 2017.

Visit the Site

Whether you’re into birding, hiking, fishing or simply want to watch a beautiful sunset from an observation tower, do yourself and your family a favor and plan a trip to Hennepin and Hopper lakes.

Site Location: Hennepin and Hopper lakes are east of the Illinois River, west of Illinois Route 26, and directly south of the village of Hennepin.

Hours of Operation: Open daily from dawn to dusk for hiking, nature viewing and bird watching.

Lake Access: Kayaking, canoeing and boating (without gas motors) is allowed from May 1 through September 30. The site is open to fishing mid-May through early September. No boating or paddling is permitted on the lakes from October 1 through April 30 to avoid disturbing migrating waterfowl.

Hiking Trails: Trails include the 2.7 mile Oak Ridge Trail, 1 mile Seep Trail, and the 0.5 mile Prairie Wetland Boardwalk. A 30-foot observation tower near the eastern boundary provides panoramic vistas.

Visit The Wetlands Initiative website for more information.

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Russ Blogg started with the Illinois Department of Natural Resources in 2008 as a Natural Heritage Resident Intern, and now is a Natural Heritage Biologist based in LaSalle County.