1-500 AD. Excavations by Dan Morse and Richard Polhemus in 1963 uncovered what they believed was an oval-shaped house, a large hearth, and various refuse pits. Morse and Polhemus agreed that the mounds were mostly built during the Middle Woodland period. The state purchased the prehistoric property in 1965 from the Williams and Saul families. It was added to the National Register of Historic Places that same year. In the 1970s, John Broster of the Tennessee Division of Archaeology carried out extensive investigations of the site's Western section and the Mound 12 Sector. Broster uncovered a human cremation pit and evidence of Early Woodland-period habitation at Mound 12. Broster's team also found a number of "exotic" artifacts at the Cochran area. This suggested Pinson Mounds may have been a "manufacture" area for grave goods, or a regional trade center. In the 1980s, Robert Mainfort discovered six tombs in the Twin Mounds, one of which contained the remains of eight young women wearing headdresses with copper adornments. Another tomb had four older men, one of whom had been buried with two round rattles bearing abstract designs. Mainfort also uncovered a single burial in Mound 31 and evidence of food offerings at the base of the mounds. Excavations carried out prior to construction of park facilities uncovered a possible habitation area at Mound 11 and a large number of 19th-century artifacts. In the late 1990s, four additional mounds were verified as prehistoric, bringing the total to 17. The function of the Pinson Mounds The Middle Woodland natives most likely built the Pinson Mounds primarily for religious ceremonial purposes, although their motives have yet to be established definitively. The Ozier Mound contains no burials and because of its shape, ramped and flat-topped, it was most likely used as a ceremonial platform. It is one of the oldest such mounds in the Eastern Woodlands region. At least three of the mounds— 6, 12, and 31— contain burials or cremations. Excavations have turned up a relatively scant amount of cultural material (e.g., arrowheads and pottery fragments), which points to a lack of permanent habitation at the Pinson Mounds site. Some evidence suggests that the layout of the Pinson Mounds might be due to astronomical alignment, and expresses the people's cosmology, as is the case at some later mound complexes, such as Cahokia. The corners of Sauls' Mound, for instance, face the four cardinal directions. The