Walnut Woods State Park is a state park in Polk County, Iowa, United States, located in suburban West Des Moines.

Within the Des Moines metropolitan area, the park preserves a bottomland hardwood forest featuring the largest natural stand of black walnut trees in North America.

[2] The Raccoon River meanders through the 260-acre (110 ha) park, providing fishing and canoeing opportunities.

The park also provides picnic areas, a limestone lodge built in the 1930s, and a small campground with 22 sites.

More than 90 bird species have been seen in the park.