had evolved into the Caddoan Mississippian culture. By 1400 AD Plaquemine had started to hybridize through contact with Middle Mississippian cultures to the north and became what archaeologist term Plaquemine Mississippian. These peoples are considered ancestral to historic groups encountered by the first Europeans in the area, the Natchez and Taensa peoples. The Caddoan Mississippians covered a large territory, including what is now eastern Oklahoma, western Arkansas, northeast Texas, and northwest Louisiana. Archaeological evidence that the cultural continuity is unbroken from prehistory to the present, and that the direct ancestors of the Caddo and related Caddo language speakers in prehistoric times and at first European contact and the modern Caddo Nation of Oklahoma is unquestioned today. Significant Caddoan Mississippian archaeological sites in Louisiana include Belcher Mound Site in Caddo Parish and Gahagan Mounds Site in Red River Parish. Native groups at time of European settlement The following groups are known to have inhabited the state's territory when the Europeans began colonization: The Choctaw nation (Muskogean): The Bayougoula, in areas directly north of the Chitimachas in the parishes of St. Helena, Tangipahoa, Washington, East Baton Rouge, West Baton Rouge, Livingston, and St. Tammany. They were allied with the Quinipissa-Mougoulacha in St. Tammany parish. The Houma in the East and West Feliciana and Pointe Coupee parishes (about 100 miles (160 km) north of the town named for them). The Okelousa in Pointe Coupee parish. The Acolapissa in St. Tammany parish. They were allied with the Tangipahoa in Tangipahoa parish. The Natchez nation: The Avoyel, in parts of Avoyelles and Concordia parishes along the Mississippi River. The Taensa, in northeastern Louisiana particularly Tensas parish. The Caddo Confederacy: The Adai in Natchitoches parish The Natchitoches confederacy consisting of the Natchitoches in Natchitoches parish The Yatasi and Nakasa in the Caddo and Bossier parishes, The Doustioni in Natchitoches parish, and Ouachita in the Caldwell parish. The Atakapa in southwestern Louisiana in Vermilion, Cameron, Lafayette, Acadia, Jefferson Davis, and Calcasieu parishes. They were allied with the Appalousa in St. Landry parish. The Chitimacha in the southeastern parishes of Iberia, Assumption, St. Mary, lower St. Martin, Terrebonne, Lafourche, St. James, St. John the Baptist, St. Charles, Jefferson, Orleans, St. Bernard, and Plaquemines. They were allied with the Washa in Assumption parish, the Chawasha in Terrebonne parish, and the Yagenechito to the east. The Tunica in northeastern parishes of Tensas, Madison, East Carroll and West Carroll, and the