Walnut Woods encompasses 260 acres of wooded bottomland along the Raccoon River. Within the park lies a large surviving natural stand of black walnut trees. More than 90 species of birds have been identified along the numerous foot and bridle trails throughout the park and along the river.

The valley in which Walnut Woods is located was created by the meandering of the Raccoon River. Since the park elevation is not much higher than the normal river level, constant changes can be seen in its banks. The most dramatic is where the river channel runs against the western edge of the park. Constant churning and washing in the past removed tons of soil, sand and gravel. In the mid-1980s, the most vulnerable areas of the riverbank were protected by rock "riprap" and special jetties designed to minimize erosion.

The shady campground is a popular place for a family "get-a-way." There are 23 campsites, 8 with electric hookups. The park has modern restrooms and an RV dump station. There are no shower facilities. The campsites are nestled among shade trees and have gravel pads, picnic tables and fireplaces. Starting February 13, 2006 advance campsite reservations can be booked through the park reservation system. Half of the campsites are still available for self-registration on a first-come, first-serve basis.