What you have to remember was that the Oregon Trail was not just a lot of people in wagons bumping along. The majority of living things that moved along the Oregon Trail were animals
There were oxen and mules to pull the wagons, of course, but the people moving west were farmers, or hoped to be farmers, and if they were to succeed, they needed to take their herds of cattle and other animals with them. All these animals needed feeding, and not only did this slow down the pace of travel, but it also controlled when they traveled.
