No, the density was never high on the central prairies. Until the Indian people got horses, they had little mobility (on foot only with maybe a dog pulling a travois) and little ability to hunt the buffalo. Apparently the Lakota people lived in the forests of the eastern US before the whites came. They were driven west century by century until they finally found their way to the great plains, perhaps as late as the mid-1700s. So that horse and tipi culture of the Lakotas was not one that existed very long.