Thoreau Wildlife Preserve

The newest ACRES preserve is already a familiar name in Defiance, Ohio. ACRES acquired the 250-acre Thoreau Wildlife Reserve in late 2025, but its restoration from overworked farmland to nature sanctuary began in 1989.

From Farmland to Sanctuary

Over the years, the Diehl family and local volunteers worked to transform the land into a space the community could enjoy. They amended the soil, installed a meadow, planted trees and built a dam to create Walden Pond. The property opened to the public in 2020, offering trails and a nature center.

Thoreau Wildlife Reserve will continue welcoming visitors to enjoy its scenic tranquility as ACRES stewards in a new chapter of efforts to return the land to a more historically natural state.

Restoring the Great Black Swamp

Restoration efforts at Thoreau Wildlife Reserve are part of a larger project to protect and restore elements of the historic Great Black Swamp in northwest Ohio. Extensive swamps and marshes once covered this area, interspersed with mesic forests and occasional dry ridges dominated by oak and hickory trees.

The region was a hotspot of diversity, including many species restricted to wetlands and even unique to the region. Over time, the habitats supporting this diversity were lost to increasing agricultural pressures, and these species became increasingly rare.

Partnering for the Future

Over the next several years, ACRES will work closely with Ducks Unlimited, the Ohio Department of Natural Resources: Division of Wildlife and other local partners to retire 87 acres of remaining agricultural fields and restore nearly 100 acres back to functional forested wetlands, flatwoods and emergent wetlands.

Once restored, these 250 acres within the Buckskin Creek-Tiffin River Watershed will slow runoff, filtering sediment and reducing nutrient pollution before it reaches the Tiffin and Maumee Rivers. The poorly drained silt-clay soils at this property are common on lake plain flats, making farming difficult. What was once a hindrance to successful crop production will now be perfect for planned restoration efforts.

A Living Reminder

On a recent visit to the property, the ACRES stewardship crew watched a barred owl swoop across a snowy field, and a brightly pelted fox trot through frozen grass mounds at the edge of Walden Pond. The wildlife sightings were a reminder of how much life the land supports.

Thoreau Wildlife Reserve provides a chance to witness the impact that caring for a large property can have on local plant and animal populations 50, 200 and 1,000 years into the future. As ACRES celebrates the Year of Water, it is fitting that we also begin a project directly focused on restoring water resources at a new property!

With this acquisition, ACRES now protects seven properties and 438 acres across northwest Ohio. Trails at Thoreau Wildlife Reserve are open to the public from dawn to dusk, with parking at 10485 Haller Road, Defiance, Ohio 43512.