The Nature Conservancy. Protecting nature. Preserving life.™

Why You Should Visit

This is a great place to see prairie wildflowers, butterflies and grassland birds.

This preserve is a remnant of dry prairie that has managed to survive in a mostly agricultural landscape, probably because the limestone bedrock beneath the soil lies too close to the surface to permit cultivation.

Location

Southwestern Wisconsin: 30 miles west of Madison in Dane and Iowa counties, in the "Driftless Area" — the only region in the state left untouched by the glaciers.

Hours

Open year-round, dawn to dusk (except during the winter when plowed snow prevents off-road parking)

Conditions

There are no trails here, and poison ivy is abundant — so be careful!

Why the Conservancy Selected this Site

Thomson is a remnant of the past. Prior to settlement, many hilltops and steep slopes in this part of the state were covered with dry prairie vegetation. Today, this is one of the few remaining dry prairies in the state.

In addition, the prairie is home to a diverse natural community: More than 68 species of plants grow here, and 34 species of birds nest or feed here.

What the Conservancy Has Done/Is Doing

Little remains of Wisconsin's once extensive grasslands. Those that have managed to survive, like Thomson Memorial Prairie, are small, isolated and fragmented. To recreate a larger grassland ecosystem, these prairie remnants must be carefully managed and expanded.

As of January 3, 2012, the Conservancy owns and manages 607 acres. With the help of volunteers, we are working to restore the degraded prairie and agricultural land surrounding the preserve through a combination of planting, prescribed burning and exotic species control.

How This Site was Named

The Conservancy named the area Thomson Memorial Prairie in recognition of John and Olive Thomson, longtime friends and stewards of the prairie. In honor of their deceased son Douglas, the Thomsons established a fund for land acquisition at the prairie.