Where was evidence of an advanced ancient tribe found in Oklahoma?

The evidence of an advanced ancient tribe was found at Spiro Mound, which is located in the southeastern region of Oklahoma. This archaeological site is significant because it was a major ceremonial center for the people of the Mississippian culture, known for their complex societal structure, advanced arts, and extensive trade networks. The artifacts discovered at Spiro, including pottery, jewelry, and burial goods, indicate a high level of craftsmanship and social organization. The site is recognized for its large burial mounds that contained elaborate grave offerings, suggesting that it held great importance to the culture that inhabited the area. Spiro Mound provides invaluable insights into the life and practices of the ancient tribes in Oklahoma, illustrating their sophistication and influence in the region.