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A meandering section of the Mukwonago River

Mukwonago River: A Guide to Preserves in a Surprisingly Pristine Watershed

August 10, 2026  |  Topics: Places

By Eddee Daniel

The Mukwonago River is either one of the cleanest rivers in southeast Wisconsin, one of the cleanest in the state, or one of the cleanest in the country, depending on who you ask (and it may well be all three). By all accounts, however, the river and its watershed are pristine enough to be of global ecological significance. It is home to fifty-six species of fish. To put that statistic into perspective, a watershed of its size is considered excellent if it has over twenty species. Fifty-six is outstanding!

The good news goes way beyond fish. There are at least fifteen species of freshwater mussel, the most threatened family of animals in North America. Being filter feeders, mussels are particularly sensitive to water quality, which has been deteriorating worldwide. The river and environs also support a great diversity of native plants and wildlife, such as waterfowl, reptiles, amphibians, insects, aquatic and wetland plants. One of the last and largest stands of wild rice in Southeastern Wisconsin can be found in the watershed. It is a refuge for such animals as sandhill cranes, tree frogs, mink, red fox, butterflies and dragonflies.

The confluence of the Mukwonago River (left) with the Fox River, into which it drains over 47,000 acres of watershed. The Fox River flows south until it meets the Illinois River. While the Mukwonago River appears in this photo to be as large as the Fox, it is far shallower.
The confluence of the Mukwonago River (left) with the Fox River, into which it drains over 47,000 acres of watershed. The Fox River flows south until it meets the Illinois River. While the Mukwonago River appears in this photo to be as large as the Fox, it is far shallower.

It isn’t a grand river. Just fourteen miles long and seldom more than a few feet deep. I’ve kayaked a few stretches, which is possible when the water level is sufficiently high. But it can be quite challenging due to the generally shallow depths and channels frequently clogged with vegetation. However unassuming, the Mukwonago River and its tributaries drain a watershed that is over 47,000 acres in area. What is at least as remarkable as the quality of this exceptional watershed itself is the fact that all of it is within an hour of Milwaukee, in Wisconsin’s most urbanized region.

No river can remain pristine on its own, especially in a region with an expanding human population like this one. It requires a lot of intentional intervention, especially the preservation of substantial amounts of land within the watershed, uplands along with wetlands. To that end a number of important organizations have made the Mukwonago River watershed a focus of conservation efforts. These include the Wisconsin Department of Natural Resources (DNR), Waukesha County, The Nature Conservancy, The Prairie Enthusiasts, Waukesha County Land Conservancy (WCLC), and Friends of the Mukwonago River.

Lakewood Farms Preserve, one of six properties owned and maintained by the Waukesha County Land Conservancy, which has recently announced a merger with Friends of the Mukwonago River.
Lakewood Farms Preserve, one of six properties owned and maintained by the Waukesha County Land Conservancy, which has recently announced a merger with Friends of the Mukwonago River.

The timing of this story coincides with the recent announcement of a merger between WCLC, and Friends of the Mukwonago River. “This is an exciting new chapter for conservation in our community,” says Allison Heine de Romero, Executive Director of WCLC. “The Waukesha County Land Conservancy is honored to carry this important work forward, ensuring the legacy of protecting the Mukwonago River continues with renewed strength and vision. By adding this important conservation effort to our mission, we can expand our ability to protect the river and surrounding lands for future generations.” WCLC owns and maintains six preserves within the watershed.

For its part, The Nature Conservancy (TNC) considers the Mukwonago River so important that it established one of only three worldwide Nature Conservancy Wetlands Network field stations in the watershed at its Pickerel Lake Fen Preserve. (The other two are in Utah and the Amazon River Basin.) TNC maintains three other preserves within the watershed, including the largest, Lulu Lake State Natural Area, which is jointly administered by TNC and DNR.

The Nature Conservancy’s Mukwonago River Watershed field station (foreground) is located on its Pickerel Lake Fen Preserve near East Troy. It is one of three Nature Conservancy Wetlands Network field stations in the world.

The many conservation properties serve a number of purposes beyond preserving beneficial wildlife habitats and protecting water quality. The primary source of water in the river is groundwater discharge, meaning the river is spring fed. At least one of these springs is easy to access at the end of a trail in the Lulu Lake preserve. I’ve filled my water bottle from gushing groundwater there. Definitely refreshing after a strenuous hike on glacial terrain! The rates of groundwater recharge, or absorption of rainfall, is significant due to the amount of protected, undeveloped land in the watershed. Overdevelopment of the watershed would threaten this phenomenon, making the acquisition of additional preserves an important goal.

Although secondary to their conservation roles, some of the preserves provide opportunities for passive recreation. This is particularly important given their proximity to Milwaukee! Hiking, birding and wildlife viewing are prominent pastimes. Some are open to hunting in season. While much of the river can be challenging to kayak, as stated earlier, there is one section that is very popular for this sport. A substantial channel of the Mukwonago River connects Eagle Spring Lake with Lulu Lake, making it easy to navigate. Be forewarned, however: motor boats are allowed there, too. If you’re able to avoid weekends and holidays, however, I’ve rarely found it to be busy.

An easy to navigate channel connects Eagle Springs Lake with Lulu Lake, making it very popular for kayaking -- and motor boating.
An easy to navigate channel connects Eagle Springs Lake with Lulu Lake, making it very popular for kayaking — and motor boating.

The images that accompany this story are essentially a visual tour of parks and preserves within the Mukwonago River watershed. I’ve attempted in the past several months to visit as many as I could locate. There are too many to include more than one image per place for most of them (seventeen, if my count is accurate). But to make up for it, I’ve also created a Flickr album with many additional images in order to provide a more comprehensive visual guide for those who wish to delve further. As usual, the links in the captions will take you to additional information, if available, about each place.

Map of the Mukwonago River Watershed. Source: Friends of the Mukwonago River.
Map of the Mukwonago River Watershed. Source: Friends of the Mukwonago River.

Guide to Parks and Preserves in the Watershed

Beulah Bog State Natural Area, East Troy. A rare undisturbed kettle bog with many unusual plants more typical of northern bogs. A short hike takes you to a boardwalk that leads out onto the bog.
Beulah Bog State Natural Area, East Troy. A rare undisturbed kettle bog with many unusual plants more typical of northern bogs. A short hike takes you to a boardwalk that leads out onto the bog.
Chapman-Trupke Preserve, a Waukesha County Land Conservancy preserve adjacent to Old World Wisconsin. A well-maintained trail loops around the property, but the entrance to the parking area can be a challenge to find!
Chapman-Trupke Preserve, a Waukesha County Land Conservancy preserve adjacent to Old World Wisconsin. A well-maintained trail loops around the property, but the entrance to the parking area can be a challenge to find!
Crooked Creek Preserve, one of The Nature Conservancy properties. This preserve, with kettle lakes and oak savanna, protects a major portion of the headwaters of the watershed. A small parking lot provides access to a hiking trail.
Crooked Creek Preserve, one of The Nature Conservancy properties. This preserve, with kettle lakes and oak savanna, protects a major portion of the headwaters of the watershed. A small parking lot provides access to a hiking trail.
Davis Preserve. Former agricultural land being restored, mostly to wetlands, by Waukesha County Land Conservancy. Contiguous with the Mukwonago River Unit of the Kettle Moraine State Forest.
Davis Preserve. Former agricultural land being restored, mostly to wetlands, by Waukesha County Land Conservancy. Contiguous with the Mukwonago River Unit of the Kettle Moraine State Forest.
Eagle Center Prairie Preserve. Designated a State Natural Area by the DNR, owned and maintained by Waukesha County Land Conservancy. Features remnant oak savanna and prairie on undulating glacial terrain. Go to link for directions if you wish to visit.
Eagle Center Prairie Preserve. Designated a State Natural Area by the DNR, owned and maintained by Waukesha County Land Conservancy. Features remnant oak savanna and prairie on undulating glacial terrain. Go to link for directions if you wish to visit.
Kettle Moraine State Forest - Mukwonago River Unit. 970 acres on the Mukwonago River that are being restored to nature after its former life as Rainbow Springs Golf Resort. Unlike the other units of the Kettle Moraine State Forest, this one is minimally developed. There is a road that once served the golf course and some trails, but no other amenities. Entrances on Hwy LO and Hwy E.
Kettle Moraine State Forest – Mukwonago River Unit. 970 acres on the Mukwonago River that are being restored to nature after its former life as Rainbow Springs Golf Resort. Unlike the other units of the Kettle Moraine State Forest, this one is minimally developed. There is a road that once served the golf course and some trails, but no other amenities. Entrances on Hwy LO and Hwy E.
1800-acre Lulu Lake State Natural Area is co-owned by the DNR and The Nature Conservancy. It features a diverse mix of wetlands and uplands shaped by the glaciers, along with over 50 acres of oak savanna, a globally rare ecosystem. The 95-acre kettle lake is accessible by boat from Eagle Springs. The scene above is a small pond at a headwaters spring feeding the Mukwonago River.
1800-acre Lulu Lake State Natural Area is co-owned by the DNR and The Nature Conservancy. It features a diverse mix of wetlands and uplands shaped by the glaciers, along with over 50 acres of oak savanna, a globally rare ecosystem. The 95-acre kettle lake is accessible by boat from Eagle Springs. The scene above is a small pond at a headwaters spring feeding the Mukwonago River.
Another Waukesha County Land Conservancy property, Meyer Preserve is dominated by hilly glacial topography, along with the wetland pictured above. A steep dirt track leads up from Hwy E to a parking area, but there is no sign at the entrance.
Another Waukesha County Land Conservancy property, Meyer Preserve is dominated by hilly glacial topography, along with the wetland pictured above. A steep dirt track leads up from Hwy E to a parking area, but there is no sign at the entrance.
Miniwaukan Park and Mukwonago River State Natural Area. The Village of Mukwonago park, mainly playing fields, sits adjacent to the State Natural Area, which includes a stretch of the river that is one of the most biologically-rich mussel habitats in the state.
Miniwaukan Park and Mukwonago River State Natural Area. The Village of Mukwonago park, mainly playing fields, sits adjacent to the State Natural Area, which includes a stretch of the river that is one of the most biologically-rich mussel habitats in the state.
A family of ospreys inhabits a tower erected for the purpose at the west end of Minors Park, another Village of Mukwonago park that stretches along Hwy LO near the village center and adjacent to the Phantom Lake wetlands.
A family of ospreys inhabits a tower erected for the purpose at the west end of Minors Park, another Village of Mukwonago park that stretches along Hwy LO near the village center and adjacent to the Phantom Lake wetlands.
Mukwonago Park. Unlike most of the preserves in this guide, this Waukesha County Park is fully developed for recreation, featuring family and group campgrounds, a beach, picnic shelters, and a dog exercise area, among other things. An entrance fee is required.
Mukwonago Park. Unlike most of the preserves in this guide, this Waukesha County Park is fully developed for recreation, featuring family and group campgrounds, a beach, picnic shelters, and a dog exercise area, among other things. An entrance fee is required.
Between Eagle Spring and Phantom Lakes, the river is designated by the DNR as an Exceptional Resource Water, with clear, warm water, a maximum depth of 2 feet and one of the largest wild rice patches in SE Wisconsin. Identified on signage as Mukwonago River Fish & Wildlife Habitat Area.
Between Eagle Spring and Phantom Lakes, the river is designated by the DNR as an Exceptional Resource Water, with clear, warm water, a maximum depth of 2 feet and one of the largest wild rice patches in SE Wisconsin. Identified on signage as Mukwonago River Fish & Wildlife Habitat Area.
Mukwonago River Oak Barrens. The only preserve in the watershed owned and maintained by The Prairie Enthusiasts. It protects sand barren habitat, one of the rarest ecosystems in SE Wisconsin. It is open to the public, but there is no sign and often a chain across the entrance. Click the link for directions.
Mukwonago River Oak Barrens. The only preserve in the watershed owned and maintained by The Prairie Enthusiasts. It protects sand barren habitat, one of the rarest ecosystems in SE Wisconsin. It is open to the public, but there is no sign and often a chain across the entrance. Click the link for directions.
The Newell and Ann Meyer Nature Preserve is a 652-acre property owned and maintained by The Nature Conservancy. A trail system loops through woodland, across prairies and alongside wetlands. The property protects springs that form a major portion of the headwaters of the Mukwonago River.
The Newell and Ann Meyer Nature Preserve is a 652-acre property owned and maintained by The Nature Conservancy. A trail system loops through woodland, across prairies and alongside wetlands. The property protects springs that form a major portion of the headwaters of the Mukwonago River.
Although 373-acre Lower Phantom Lake is called "Phantom" due to local spooky folklore, it might as well be called that because so much of it is wetland instead of open water. Seen here from Minors Park on the north.
Although 373-acre (Lower) Phantom Lake is called “Phantom” due to local spooky folklore, it might as well be called that because so much of it is wetland instead of open water. Seen here from Minors Park on the north.
If there is a Mukwonago River wilderness, this seems to be the heart of it! A Waukesha County-owned undesignated property that fills a gap in the protection of the river. It is surrounded on three sides by the Kettle Moraine State Forest. There is a small parking lot off Hwy LO and a paved drive leading into it. The only trails are rudimentary, though, as it's not developed for recreation.
If there is a Mukwonago River wilderness, this seems to be the heart of it! A Waukesha County-owned undesignated property that fills a gap in the protection of the river. It is surrounded on three sides by the Kettle Moraine State Forest. There is a small parking lot off Hwy LO and a paved drive leading into it. The only trails are rudimentary, though, as it’s not developed for recreation.

For additional photos from the many parks and preserves in the Mukwonago River Watershed go to my Flickr album.

Additional links of interest:

The Nature Conservancy: Mukwonago River Watershed

Waukesha County Land Conservancy

Wisconsin DNR

Waukesha County Parks & Recreation

The Prairie Enthusiasts – Glacial Prairie Chapter

Friends of the Mukwonago River (website still active)

Eddee Daniel, writer/photographer, is a board member of Preserve Our Parks, the Program Director of A Wealth of Nature, and editor of The Natural Realm blog. Read more or subscribe at awealthofnature.org. Also available by arrangement for group presentations and guided tours.

Waukesha County Land Conservancy and Waukesha County Parks are project partners of A Wealth of Nature.

The Natural Realm blog is part of A Wealth of Nature, which is a program of Preserve Our Parks.

About Preserve Our Parks

Preserve Our Parks, Inc. is an independent nonprofit organization dedicated to the preservation of parks and green spaces.  Our mission: To advocate for and promote Milwaukee area parks and open spaces and to strive to protect the tenets of Wisconsin’s Public Trust Doctrine. 

For more than 25 years, we have been a leader in advocating for the protection of Milwaukee County park lands, halting many proposals to develop, privatize, or sell local parkland and lakefront spaces.  More information about POP, including past accomplishments, is available at www.preserveourparks.org.

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