Nelson Dewey State Park
Bluffs and Prairies Have Many Birds and Animals

Nelson Dewey State Park's high bluffs overlooking the Mississippi River and native and restored prairies attract varied birds and wildlife.

Nelson Dewey's Bluff Tells a Story


The Prairie Trail goes by a rock outcrop over the river valley.
DNR Photo

One of the most interesting features of the park is its geology. You can read the origin of the park’s bluff by examining the exposed rock.

Wisconsin was once a mountainous region that eroded to a somewhat flat plain. This area of the state then warped down and up repeatedly. When it was down, the area was covered by invading seas. At the bottom of these seas, deposits of sand, clay, mud, and limy ooze formed the rock which underlies the park. Tremendous pressure and cementation over millions of years changed these soft deposits into sandstone and limestone.

Since the last upwarp of the land, water has been shaping the landscape. A dendriticdrainage pattern (shaped like a branching tree) formed on the level surface of the soft rock. With the passing of time the water courses eroded downward, creating the deep, picturesque valleys of today.

Dewey Heights Prairie

The Dewey Heights Prairie was dedicated as a state natural Area in 2000. This 27- acre prairie remnant and all the plants, animals and insects that live here are protected. This small grassland is a tiny portion of the thousands of acres of prairie that existed here in Southern Wisconsin more than 200 years ago. Farming and invasion of other species has dwindled the prairies to a few tiny islands.

Prairie means tall grassland. Grasslands need fire to burn off the invaders such as trees, brush and weeds in order to grow. Huge Bur Oaks, with their thick bark to protect them from fire, grew together in areas called savannas. The prairie was home to many animals that are not here now. Eastern Elk, buffalo, prairie chickens, wolves, and even the wild turkey vanished from the prairie for almost 100 years.

The prairie is a very special place. Please protect it by staying on the trail and not picking the plants or harassing or bothering any of the animals or insects.

For More Information

Nelson Dewey State Park
P.O. Box 658
Cassville, WI 53806
Phone (608) 725-5374

Last Revised: Friday May 29 2009