Whatever outdoor activities you enjoy, you'll find that a variety of recreational opportunities await you at Interstate State Park. It's Wisconsin's oldest state park, established in 1900. The park is in Wisconsin's Forest Transition landscape, across the Saint Croix River from Minnesota's Interstate State Park. River with rocky banks The scenic Dalles of the St. Croix gorge separates Wisconsin and Minnesota. Wisconsin Department of Tourism Photo Wisconsin's Interstate Park has two campgrounds with a total of 85 family campsites, and a primitive group camp that accommodates 60 people.