 The Native Americans that lived along the Missouri had access to ample food , water , and shelter . Many migratory animals inhabited the plains at the time , providing them meat , clothing , and other everyday items ; there were also great riparian areas in the river 's floodplain that provided them with natural herbs and staple foods . No written records from the tribes and peoples of the pre @-@ European period exist because they did not use writing . According to the writings of explorers , some of the major tribes along the Missouri River included the <unk> , <unk> , Omaha , <unk> , <unk> , Lakota , Sioux , <unk> , Hidatsa , Mandan , <unk> , <unk> <unk> and <unk> . 
