Lakes / Colorado / Summit County / Green Mountain Reservoir
Green Mountain Reservoir, Colorado
2,044 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Colorado
39.87 degrees N, 106.29 degrees W - Summit 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 Green Mountain Reservoir Stacks Up
- Larger than 97% of the 778 lakes counted in Colorado.
- About 55 miles from Boulder, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Lower Cataract Lake | Summit | 3.3 mi | 47 acres |
| Black Lake | Summit | 5.6 mi | 89 acres |
| Upper Cataract Lake | Summit | 6.2 mi | 40 acres |
| Bubble Lake | Summit | 8.6 mi | 27 acres |
| Upper Slate Lake | Summit | 9.1 mi | 27 acres |
| Williams Fork Reservoir | Grand | 11 mi | 1,549 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Green Mountain Reservoir
How Big Is Green Mountain Reservoir?
Green Mountain Reservoir covers 2,044 acres in Summit County, Colorado.
What Is the Largest Lake in Summit County?
Dillon Reservoir is the largest lake in Summit County, at 3,219 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 79947672). Verified October 30, 2026.