If my history is correct, the Sioux tribe was kicked out of the Northeast by other tribes and emigrated to the SD region.
"Ancestral Sioux The ancestral Sioux most likely lived in the Central Mississippi Valley region and later in Minnesota, for at least two or three thousand years. The ancestors of the Sioux arrived in the northwoods of central Minnesota and northwestern Wisconsin from the Central Mississippi River shortly before 800 AD.
What I was referring to is the Origin Myth they have subscribed to in their religion as it was taught to me by an anthropology Professor at South Dakota State University, low many years ago.