9. Self-Sustaining Rivers

Colorado and Hawaii stand out in the United States for a unique hydrological characteristic: they are the only states where every river originates within their own borders. This means that the journey of every river in these states begins from sources located on their own land, be it mountain springs in Colorado’s Rocky Mountains or the volcanic slopes of Hawaii.

Colorado, with its high elevation, serves as a watershed that feeds rivers flowing to various parts of the continent, while Hawaii’s isolated island geography ensures that its rivers spring from local sources before making their way to the ocean.