The people of the Adena Culture were some of the first to construct burial mounds and earthworks in the Ohio River Valley. Early Adena sites date to between 1000 and 200 BC and usually consist of either an isolated burial mound or a small group of no more than two or three tumuli. The early mounds contain extended and flexed burials, cremations in pits, and bark-lined tombs and represent the generational burial places of local communities or hamlets. Beginning sometime around 200 BC and continuing to around 300 AD, multiple dispersed Adena communities began to assemble together at specific ritual areas to construct large burial mounds and ceremonial earthwork enclosures. This development in Late Adena is considered to represent the
