Places We Protect

Crooked Creek Preserve


at Crooked Creek Preserve.
Autumn at Crooked Creek Preserve. © Gerald H. Emmerich, Jr.

The Conservancy is restoring the preserve to prairie and oak savanna.



Why You Should Visit

Crooked Creek Preserve takes its name from the winding river that runs through it. The preserve harbors a major portion of the headwaters of the Mukwonago River. 

It is a landscape of steep ridges, kettle lakes, and wetlands inhabited by sandhill cranes and other interesting plants and wildlife. It’s also a great place to see and participate in restoration of the land as Conservancy volunteers remove pine plantations and restore parts of the preserve to prairie and oak savanna.


For more information about the preserve, contact the Conservancy's local office:

N8740 Pickeral Lake Rd.
East Troy WI 53120-1836
Tel: 262-642-7276

Why TNC Selected This Site

Because of the high-quality stream surrounded by wetlands and oak openings, which provides habitat for rare fish, mussels and plants.

An oak opening is dominated by clustered, open-grown bur oaks and white oaks, and shagbark hickory.  The ground is covered with prairie and forest plants.

Before agricultural settlement there were more than 5.5 million acres of oak savanna in Wisconsin.  Today only about 500 acres survive, some of which are found at the Crooked Creek Preserve.  The Conservancy is using fire and manual removal of non-native plants to restore and maintain them.

What TNC Has Done/Is Doing

Crooked Creek Preserve has been a sanctuary for plants, birds, and other animals since Thomas and Florence Russell of Chicago turned the land into a nature conservancy and summer retreat.

The Nature Conservancy bought the first 197-acre parcel of land from Aurora University (formerly George Williams College) in August 2000. In September 2017, we purchased the 107-acre former Chapman Hills Girl Scout Camp. This beautiful property with its wetlands, oak savanna and upland forest connects formerly-isolated parts of the preserve and creates a larger expanse of habitat for wildlife.

The Conservancy has spent nearly 10 years removing white and red pines from the preserve to prevent soil erosion into the river and to restore the oak savannas that once existed on the property. The pines don’t naturally occur in the area but have spread over the years from sites where they were planted, surrounding many of the oak trees native to the area, reducing the sunlight that reaches them, and starting to kill their lower branches.

Crooked Creek Preserve is located within the Mukwonago River Watershed project area.  The Conservancy has an office and staff in the East Troy area, and we are working cooperatively with many different public and private partners to accomplish the following:

  • Protect the water quality of and natural areas within the Mukwonago River Watershed.
  • Manage our preserves to maintain rare natural communities and provide habitat for fish, mussels, amphibians and reptiles.
  • Work with individuals and organizations concerned with the health of the watershed to help balance watershed protection with human needs and economic health.




Open year round, dawn to dusk


591 acres

Explore our work in this region

What to See: Plants

Wetlands dominate the eastern portion of the preserve, and the Mukwonago River flows across the southeastern corner.  A kettle lake with an earthen dam spills into a tributary of the Mukwonago River, and there are oak openings north of the lake.  The northern portion of the preserve is open pasture and grassland, which will eventually be returned to prairie.

What to See: Animals

  • Fish: Of the 150 fish species native to Wisconsin, 59 can be found in the Mukwonago River and nearby Lulu Lake!  The river is home to several rare fish species, including the longear sunfish.
  • Birds: Significant species are Cooper's hawks, migrating ospreys, and nesting pairs of sandhill cranes.  Other birds you might see or hear include common yellowthroats, yellow warblers, ovenbirds, and cerulean warblers.
  • Amphibians: Spring peepers, chorus frogs, Cope's gray tree frogs, green frogs, Eastern gray tree frogs, bullfrogs, and American toads can all be seen at the preserve, some more often than others.


For more information about visiting the preserve, please follow the links below:

All of our preserve maps are now georeferenced. You can download an app on your Apple or Android device, and it will allow you to view your location, record GPS tracks, add placemarks and find places.