The Interstate State Park CCC/WPA/Rustic Style Campground at the southwest end of the Minnesota park contains six contributing properties as well. These consist of three buildings—the 1938 Sanitation Building (restrooms at the west end of the picnic area), 1938 Shelter/Refectory (in the center of the picnic area), and 1941 Combination Building (restrooms in the campground)—and three objects (the drinking fountains scattered in the picnic area) also built in 1938. The Combination Building was based on a design also used in Whitewater State Park in 1938, though the use of different local materials gives them a very different appearance. An open-sided picnic shelter with a free-standing metal fireplace was actually built in 1980 and is considered a non-contributing property to the district.