The Upper Colorado water resource region is one of 21 major geographic areas, or regions, in the first level of classification used by the United States Geological Survey to divide and sub-divide the United States into successively smaller hydrologic units. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a series of rivers.[1][2]
The Upper Colorado region, which is listed with a 2-digit hydrologic unit code (HUC) of 14, has an approximate size of 113,347 square miles (293,570 square kilometers), and consists of 8 subregions, which are listed with the 4-digit HUCs 1401 through 1408.[3]
This region includes the drainage of: (a) the Colorado River Basin above the Lee Ferry compact point which is one mile below the mouth of the Paria River; and (b) the Great Divide closed basin. Includes parts of Arizona, Colorado, New Mexico, Utah, and Wyoming.[4]