Plum Bayou culture is a Pre-Columbian Native American culture that lived in what is now east-central Arkansas from 650—1050 CE, a time known as the Late Woodland Period. Archaeologists defined the culture based on the Toltec Mounds site and named it for a local waterway.
The Baytown culture (300 to 650 CE) preceded the Plum Bayou culture, and was then followed by early Mississippian cultures, which flourished from 900—1600 CE, until diseases brought by European decimated their populations.
The Plum Bayou culture had contact with the Coles Creek culture, located along the Mississippi River, and early Caddoan cultures, located in river valleys of the Red, Ouachita, and Arkansas Rivers in Arkansas and into Oklahoma.
Exotic materials found at Plum Bayou sites reveal trade with the Ozark Plateau, West Gulf Coastal Plain, and the Ouachita Mountains.
Major Plum Bayou sites with single or multiple mounds include:
Plum Bayou culture was one of the earliest groups to build ceremonial community centers with platform mounds and rectangular plazas. They primarily lived in small villages in the uplands and floodplains of the White and Arkansas Rivers. Archaeologists divide Plum Bayou settlements into "single household, multiple household, multiple household with mound, and multiple mound sites."
Farmers grew crops such as amaranth, chenopodium, bottle gourd, knotweed, little barley, maygrass, squash, sunflower, and sumpweed. In some later Plum Bayou sites, maize was cultivated in small amounts. Supplementing their farming, Plum Bayou peoples also hunted game and gathered wild plants, such as cherries, grapes, plums, persimmons, and nuts.