Lakes / Colorado / Rio Blanco County / Allen Basin Reservoir
Allen Basin Reservoir, Colorado
83 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Colorado
40.16 degrees N, 107.05 degrees W - Rio Blanco County. State and county outlines drawn from Census boundary data; the lake marker is placed by its USGS National Hydrography Dataset coordinates, not by eye. Schematic - not a survey map.
How Allen Basin Reservoir Stacks Up
- Larger than 61% of the 778 lakes counted in Colorado.
- About 68 miles from Aspen, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Crosho Lake | Rio Blanco | 1.1 mi | 53 acres |
| Heart Lake | Rio Blanco | 3.5 mi | 28 acres |
| Sheriff Reservoir | Rio Blanco | 4.9 mi | 36 acres |
| Yamcolo Reservoir | Garfield | 7.4 mi | 184 acres |
| Gardner Park Reservoir | Routt | 7.9 mi | 50 acres |
| Upper Stillwater Reservoir | Garfield | 8.2 mi | 56 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Allen Basin Reservoir
How Big Is Allen Basin Reservoir?
Allen Basin Reservoir covers 83 acres in Rio Blanco County, Colorado.
What Is the Largest Lake in Rio Blanco County?
Big Beaver Reservoir is the largest lake in Rio Blanco County, at 205 acres.
Largest Lakes in Colorado
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | John Martin Reservoir | Bent | 11,686 acres | - |
| 2 | Blue Mesa Reservoir | Gunnison | 8,944 acres | - |
| 3 | Lake Granby | Grand | 7,075 acres | - |
| 4 | Lake Meredith | Crowley | 5,539 acres | - |
| 5 | Adobe Creek Reservoir | Bent | 4,770 acres | - |
All 778 Colorado lakes ranked by surface area
Sources: USGS NHD (The National Map NHD MapServer layer 12) named waterbodies FTYPE 390/436; counties via Census point-in-polygon lake data (ID 90214379). Verified October 30, 2026.