Colorado drainage basins Table of major drainage basins Major Drainage Basins of the State of Colorado

| Basin | Outlet | Total_Area | In_State_Area | _In_State |
|---|---|---|---|---|
| Saint Vrain Creek | South Platte River | 050 2,572km 2 993mi 2 | 035 2,572km 2 993mi 2 | A016 100% |
| Eagle River | upper Colorado River ( GrandRiver ) | 051 2,515km 2 971mi 2 | 038 2,515km 2 971mi 2 | A017 100% |
| Vermillion Creek | Green River | 052 2,500km 2 965mi 2 | 059 1,155km 2 446mi 2 | A051 46.2% |
| North Fork Gunnison River | Gunnison River | 053 2,492km 2 962mi 2 | 041 2,492km 2 962mi 2 | A018 100% |
| Fountain Creek | Arkansas River | 054 2,418km 2 933mi 2 | 042 2,418km 2 933mi 2 | A019 100% |
| Big Thompson River | South Platte River | 055 2,149km 2 830mi 2 | 045 2,149km 2 830mi 2 | A020 100% |