Native American Mound Builders During the Early and Late Woodland Periods the early Native American tribes built mounds, mostly in the Mississippi and Ohio River Valleys. There are no written records about the purpose of these mounds, so the reasons for building them remain largely speculative. Adena and Hopewell Culture and Mounds People of both the Adena and later Hopewell cultures inhabited the White River region of Mounds State Park. They constructed several mounds on the bluffs above the river. The mounds are well preserved due to the efforts of some of the earliest American settlers in the area, thus the mounds at the park in in good condition. Camping Mounds State Park has a modern campground equipped with modern restrooms and electric hook ups. A camping trip to the park allows visitors the chance to delve into the history of some of Indiana's earliest inhabitants. Hiking Two of the hiking trails in the park lead through the heart of the mounds complex as well as to the nearby visitor center in the park.