For millennia, the Confluence Region of North America, where the Ohio, Missouri, and Mississippi Rivers and their tributaries meet, was a very attractive area for Indigenous settlement, fishing, and hunting. Rivers, creeks, and other streams attracted not just wildlife but provided water for drinking and cleaning, while the forests that once covered the eastern half of the state provided raw materials and fuel for cooking. The caves within the forests and along the streams provided ready shelter for hunter and hunted alike, and tools were made from stone, bone, and wood.
Archaeologists estimate the first human hunters in Missouri to date around 9500 BCE, drawn here by woolly mammoth and giant sloths as prey. Hunter-gathering societies are believed to have begun developing around 7,000 BCE, inaugurating what is known as the Archaic period that lasted until about 1,000 BCE. At about that time, pottery may have begun to be manufactured, inaugurating what is known as the Early Woodland period, with evidence of religious rites around burial being developed. From 5500 BCE to about 400 CE, the Middle Woodland period is characterized by the development of settlements, the domestication of plants such as corn and the development of trade, which especially flourished in eastern Missouri and southern Illinois, thanks once again to travel made easier by river. From Illinois and Missouri to the north, to Louisiana and Mississippi to the south, the Mississippi River began to support a vast trading culture centered more to the east along the Ohio known as Hopewell.
Educational sites of interest related to the earliest human presence within the boundaries of the Diocese of Missouri include Mastodon State Park in Imperial, Rodgers Shelter Archaeological Site in Benton County, the Cuiver River Complex near Troy, and Native American Petroglyphs in De Soto.