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]
Subregion HUC[5] | Subregion Name[5] | Subregion Description[4] | Subregion Location[5] | Subregion Size[5] | Subregion Map |
---|---|---|---|---|---|
1401 | Colorado headwaters subregion | The Colorado River Basin to but excluding the Bitter Creek Basin, and excluding the Gunnison River Basin. | Colorado and Utah. | 9,730 sq mi (25,200 km2) | |
1402 | Gunnison subregion | The Gunnison River Basin. | Colorado | 7,930 sq mi (20,500 km2) | |
1403 | Upper Colorado–Dolores subregion | The Colorado River Basin from and including the Bitter Creek Basin to the confluence with the Green River Basin. | Colorado and Utah. | 8,250 sq mi (21,400 km2) | |
1404 | Great Divide – Upper Green subregion | The Green River Basin above the confluence with the Yampa River Basin; and the Great Divide closed basin. | Utah and Wyoming. | 20,600 sq mi (53,000 km2) | |
1405 | White–Yampa subregion | The White and Yampa River Basins. | Colorado, Utah, and Wyoming. | 13,100 sq mi (34,000 km2) | |
1406 | Lower Green subregion | The Green River Basin below the confluence with the Yampa River Basin, but excluding the Yampa and White River Basins. | Colorado and Utah. | 14,400 sq mi (37,000 km2) | |
1407 | Upper Colorado–Dirty Devil subregion | The Colorado River Basin below the confluence with the Green River Basin to the Lee Ferry compact point, but excluding the San Juan River Basin. | Arizona and Utah. | 13,500 sq mi (35,000 km2) | |
1408 | San Juan subregion | The San Juan River Basin. | Arizona, Colorado, New Mexico, and Utah. | 24,600 sq mi (64,000 km2) |