Early in the ninth century, the Caddo, several affiliated groups of people with distinct dialects and customs, moved into parts of present Arkansas, Louisiana, Oklahoma and Texas. Complex societies based on successful trade, advanced agriculture and intricate rituals soon dispersed along the rivers and creeks of the region. By the 1540s, European explorers met their descendants and wrote the first descriptions of those called Kadhadacho, meaning "Real Chief" or "Real Caddo." Locally, the Hasinai tribe of the Caddo Nation populated the area. As American settlers moved into northeast Texas in the early 19th century, they encountered the confederacy of tribes called Caddo and found cultural evidence of their ancestors, including pottery, stone tools and burial mounds. Such artifacts confirm that the Sabine River and its tributaries have supported life here for centuries. By the early 1840s, the Caddo had moved out of their ancestral homeland, settling in 1855 at the Brazos Indian Reservation near Graham (150 mi. W) and in 1859 at the Washita River in Indian Territory (Oklahoma). Today, the Caddo Nation headquarters is in Binger, Oklahoma, where members maintain cultural traditions through pottery, song, dance and language. Archeologists, ethnologists and others have worked to reconstruct the early, unrecorded history of the Caddo. Artifacts, landscape features, folklore and comparative historical accounts help tell the story of people who flourished here for a thousand years. Archeological sites discovered within the Mineola Nature Preserve on the Sabine River help enrich the record of significant contributions the Caddo made to the cultural history and development of the state of Texas. 2007