Daily mileage is also dependent on distances between campgrounds, motels, food, water or other opportunities for provisions and lodging. In part of the western US. it can be a long way between opportunities. There are some stretches that are 200 kms long with 1 or 2 places to stop, and very few good areas to wild camp. This may either reduce the mileage for a period of time from what you would have been physically capable of riding.
In Oregon's high desert you tend to stop where there is shade and water, regardless of the distance. You could wild camp almost any where, but who would want to.
