Amazing how some things end up as scientific stuff.
The Mandans, a Siouxian tribe with which I am fairly familiar, have an oral tradition that their people came to the Missouri River Valley in the Dakotas in roughly the 13th century after being driven from their homeland in the Ohio River Valley. The Mandans would always bury their dead with their feet pointed toward the Ohio River Valley.
Prior to that, Mandan tradition is that they were in the James River Valley (Virginia) and the details of the tradition, including timing, become very sketchy. It could have been up to 1000 years before. It could even have been in the solutrean era where artifacts have been discovered.
It is interesting that the Powhattans which John Smith and the Jamestown colony encountered had a corn growing and social hierarchy and lodge living structure very similar to what LaVereyandre and Lewis and Clark encountered roughly one and two centuries later, respectively. Of course the Mandans had a highly insulated earth lodge structure more adapted to the harsh climate of North Dakota than did the Powhatttans in Virginia.