The tipi as we know it today, with canvas cover, wind flaps, and offset centre, is a post-colonial structure. Early reports from the first Europeans to enter North America describe smaller structures with covers of buffalo skin, bark or mat. I would seem likely that these early structures had more in common with the choom of northern Siberia
than the great lodges painted by the likes of Edward Curtis, and it is possible that they crossed the Bering Straits land bridge along with these first human migrants. Indeed, if the theory of colonisation of North America via the Bering Bridge is accepted, then it would seem that this structure was vital to the process, for it is a long way to walk without any warm shelter for the night!
Vajda describes this journey here.
He points out that having made this difficult passage... "these Paleo-Indian big game hunters quickly spread southward into a land teeming with game as a warming climate opened gaps in the ice sheets covering northern Canada. " It is into this environment that we mist imagine the tipi first evolving.
With the loss of the ice, the movement of a tipi becomes much more difficult. Even today, in the Arctic regions, special lightweight sledges must be employed to carry the heavy poles and covers. For a Paleo-Indian, dragging a large structure around manually must have been quite a challenge. It may thus be that they actually shrunk considerably in size until the introduction of the horse in the early fifteenth century (Fazio 1995)
. (To see a skin tent moving in the arctic see here