Discover much more than just sand dunes as you bike on an interconnected trail system that spans 37 miles across the entire length of the national park. A wide variety of trails traverse the various habitats and cultural history of Indiana Dunes National Park. The varying lengths make it easy to choose the trail that's right for you. From a short easy ride to a challenging all-day trek, most of the trails are open all year and the experience will change with each season.