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 |
|---|---|---|---|---|
| San Luis Creek | San Luis Closed Basin | 025 7,000km 2 2,703mi 2 | 015 7,000km 2 2,703mi 2 | A003 100% |
| Cache la Poudre River | South Platte River | 026 4,959km 2 1,915mi 2 | 021 4,587km 2 1,771mi 2 | A034 92.5% |
| Bear Creek Basin | endorheic basin | 027 4,896km 2 1,890mi 2 | 037 2,521km 2 973mi 2 | A048 51.5% |
| Huerfano River | Arkansas River | 028 4,840km 2 1,869mi 2 | 019 4,840km 2 1,869mi 2 | A004 100% |
| Big Sandy Creek | Arkansas River | 029 4,825km 2 1,863mi 2 | 020 4,825km 2 1,863mi 2 | A005 100% |
| Bear Creek | Bear Creek Basin | 030 4,500km 2 1,737mi 2 | 039 2,500km 2 965mi 2 | A047 55.6% |