The Colorado River Geographers can tell you that the one thing that most rivers and their adjacent flood plains in the world have in common is that they have rich histories associated with human settlement and development. This especially true in arid regions which are very dependent upon water. Two excellent examples are the Nile and the Tigris-Euphrates rivers which show use the relationship between rivers and concentrations of people. However, the Colorado River is not such a good example along most segments of its course. There is no continuous transportation system that parallels the rivers course, and settlement