Getting on the Oregon Trail was a big deal. It was expensive, hard on people and animals, and it needed good timing.
This was still the time when water transport was king. People had used water transport since the dawn of time, and that is where their minds first turned in terms of travel. It was far easier to be on a boat that walking.
So the question was how far up the Missouri could they go by boat before they had to walk. The places they chose to leave the boats were called jumping off places.
