OCR Text |
Show PART II DESCRIPTION OF REGION Location and Size The Upper Colorado Region comprises the drainage basin of the Colo- rado River above Lee Ferry, Arizona, and the Great Divide Basin in south- central Wyoming. The region is on the west side of the Continental Divide and includes parts of Arizona, Colorado, New Mexico, Utah, and Wyoming. It encompasses an area of 113,496 square miles, including 109,580 square miles in the Upper Colorado River drainage and 3,916 square miles in the Great Divide Basin of Wyoming. The region is bounded on the east and north by mountains forming the Continental Divide and on the west by the Wasatch Mountains. On the south it opens to the Lower Colorado Region at Lee Ferry in northern Arizona. For the purpose of analyzing problems and selecting a framework plan, the region was divided into three hydrologic subregions comprising the natural drainage basins of the Colorado River and its two principal tribu- taries, the Green and San Juan Rivers. These areas are generally indepen- dent of each other, especially with regard to water and related land use. Total area of the region by states and subregions is shown below. The su"b- regions are delineated on the frontispiece map and are discussed in the following sections. Area by states and subregions (Unit--square miles) ___ Subregion_____Arizona Colorado Mexico Utah Wyoming Total- Green River 10,574 17,066 1/21,020 48,66O Upper Main Stem 22,168 4,024 26,192 San Juan- Colorado 6,927 5,800 9,740 16,177_____________38,64U Total_______6,927 38,542 9,740 37,267 21,020 113,496 T7 Includes Great Divide Basin of 3,916 square miles. " Green River Subregion The Green River Subregion is located in southwestern Wyoming, nortti- western Colorado, and northeastern Utah. It has an area of about 48,66O square miles or about 43 percent of the entire region, and comprises the entire drainage basin of the Green River and the Great Divide Basin. Principal tributaries of the Green River are Blacks Fork and Hams Fork in southwestern Wyoming, Yampa, and White Rivers on the western slope of ttie Continental Divide in northwestern Colorado, and the Price, Duchesne, |