They should have just used the printing press. Oh yeah, this is a culture that never invented the wheel in 5,000 years.
Just what good would a wheel have been in the breaks, bottoms and even on the prairies? Something else to break, labor intensive to create, and no roads (more labor intensive) to use it on.
For their environment, the travois did just fine. None of the mountain men or French trappers (nor even Lewis and Clark) were using a lot of wheels, either.
If it ain't broke, don't fix it.