While there were no domesticated beasts of burden to use in North America, rivers were for sure the highway of the day. Honestly they were really the best way to travel North America until fairly recently, I look at Lewis and Clark's expedition as a pretty well known example of how rivers helped humans get across the continent fairly quickly. Dugout canoes would be the simpest form of watercraft used by pre-Columbian communities, but even without taking to the water a river is a great means of travel. It is a natural marker and often will be in a relatively flat area which makes for smoother travel. The geography of North America make rivers beneficial as well as the Mississippi and Missouri, along with the Ohio and tributaries of each river, can take you basically anywhere in Eastern North America. To this day we have transport along these major rivers, I can recall a few summers back hiking along the Mississippi and just watching barges sail by for most of the day. While on foot may have been the most common means of travel, I think by river was arguably the most efficient and served as the highway system for much of Eastern North America.