Cahokia is a large urban site on the east bank of the Mississippi River valley in what is now Illinois, across the river from St. Louis, Missouri. It is the site of one of several Native American cultural and commercial centers that existed in an area bounded by the Gulf of Mexico and the present states of Oklahoma, Wisconsin, and Georgia.
Large public structures dominate the central part of the site, with smaller ones located at or near the community periphery. Large storage facilities were concentrated in two areas in the northwestern portion of the site. Near the southern edge of the urban complex is the area interpreted as a locus for butchering and meat-processing.
The Cahokia site is the largest pre-Columbian site in North America north of Central Mexico, encompassing some 3,700 square miles. It contains more than one hundred carefully constructed mounds of rammed earth and clay of various shapes and sizes. The largest of the mounds, which dominates the site, is known as Monks Mound. This monumental structure covers fifteen acres of ground and rises more than one hundred feet above the valley floor. Among structures in North America, it is second in size only to Cholula and the Pyramid of the Sun at Teotihuacán.
At the time of modern European contact, Cahokia was settled by the Cahokia tribe, which made up a part of the Illini or Illinois Nation. Other tribes in the Illinois Nation included the Kaskakia and Peoria. The Illinois Nation, along with the Wea and Piankashaw tribes, were removed in the nineteenth century to lands west of the Mississippi. These various tribal peoples are known presently as the Consolidated Peoria Tribe of northeastern Oklahoma.
The population of Cahokia at its height is estimated to have been in the tens of thousands. Numerous plazas, ceremonial areas, and ritual spaces have been excavated. These are protected as a part of the Cahokia Mounds State Park and Museum, supported by the state of Illinois and private donations. A full program of events is run on a scheduled basis, including the summer solstice celebration, storytelling and stargazing, Summer Games Field Day, Native Harvest Festival, Native American Crafts Days, and archaeological field schools.