Texas lies between two major cultural spheres of Pre-Columbian North America: the Southwestern and the Plains areas. Archaeologists have found that three major indigenous cultures lived in this territory, and reached their developmental peak before the first European contact. These were: the Pueblo from the upper Rio Grande region, centered west of Texas; the Mississippian culture, also known as Mound Builders, which extended along the Mississippi River Valley east of Texas; and the civilizations of Mesoamerica, centered south of Texas. Influence of Teotihuacan in northern Mexico peaked around AD 500 and declined over the 8th to 10th centuries.