Lakes / Montana / Gallatin County
Lakes in Gallatin County, Montana
21 lakes counted in Gallatin County - the largest is Hebgen Lake at 12,564 acres.
21
Lakes Counted
12,564 acres
Largest - Hebgen Lake
Gallatin County, highlighted, with its largest counted lakes dotted. Outlines from Census boundary data.
All Counted Lakes
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Hebgen Lake | Gallatin | 12,564 acres | About 80 ft |
| 2 | Hyalite Reservoir | Gallatin | 158 acres | - |
| 3 | Lava Lake | Gallatin | 47 acres | - |
| 4 | Mystic Lake | Gallatin | 34.8 acres | - |
| 5 | Albino Lake | Gallatin | 22 acres | - |
| 6 | Johnson Lake | Gallatin | 16 acres | - |
| 7 | Emerald Lake | Gallatin | 14 acres | - |
| 8 | Rat Lake | Gallatin | 13 acres | - |
| 9 | Heather Lake | Gallatin | 12 acres | - |
| 10 | Deer Lake | Gallatin | 12 acres | - |
| 11 | Fairy Lake | Gallatin | 11 acres | - |
| 12 | Hidden Lakes | Gallatin | 7 acres | - |
| 13 | Moon Lake | Gallatin | 6 acres | - |
| 14 | Pioneer Lakes | Gallatin | 6 acres | - |
| 15 | Blackmore Lake | Gallatin | 6 acres | - |
| 16 | Grayling Lake | Gallatin | 3 acres | - |
| 17 | Hyalite Lake | Gallatin | 3 acres | - |
| 18 | Hidden Lakes | Gallatin | 3 acres | - |
| 19 | Big Bear Lake | Gallatin | 2 acres | - |
| 20 | Lake Elsie | Gallatin | 2 acres | - |
| 21 | Lillian Lake | Gallatin | 1 acres | - |
Sources: Montana Fish, Wildlife & Parks lake data; USGS. Verified October 30, 2026.