Lakes / Colorado / Boulder County / Long Lake
Long Lake, Boulder County, Colorado
41 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Colorado
40.07 degrees N, 105.59 degrees W - Boulder 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 Long Lake Stacks Up
- Larger than 33% of the 778 lakes counted in Colorado.
- About 17 miles from Boulder, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Lake Isabelle | Boulder | 1.4 mi | 31 acres |
| Left Hand Reservoir | Boulder | 1.6 mi | 96 acres |
| Albion Lake | Boulder | 1.9 mi | 32 acres |
| Island Lake | Boulder | 3.0 mi | 34 acres |
| Silver Lake | Boulder | 3.0 mi | 105 acres |
| Goose Lake | Boulder | 3.1 mi | 40 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Long Lake
How Big Is Long Lake?
Long Lake covers 41 acres in Boulder County, Colorado.
What Is the Largest Lake in Boulder County?
Boulder Reservoir is the largest lake in Boulder County, at 536 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 128058299). Verified October 30, 2026.