Lakes / Montana / Cooney Reservoir
Cooney Reservoir, Montana
733 acres
Surface Area
4,244.32 ft
Surface Elevation
Where It Sits, and How Deep It Goes
Locator - Montana
45.44 degrees N, 109.22 degrees W - Carbon County. State and county outlines drawn from Census boundary data; the lake marker is placed by its Montana Fish, Wildlife & Parks coordinates, not by eye. Schematic - not a survey map.
How Cooney Reservoir Stacks Up
- The largest lake in Carbon County among those counted.
- About 42 miles from Billings, as the crow flies.
- 12 fish species on the FWP list for this lake.
Fish Species
Black CrappieBrown TroutBurbotLake ChubLongnose SuckerMountain SuckerMountain WhitefishRainbow TroutWalleyeWhite SuckerYellow PerchYellowstone Cutthroat Trout
Species recorded for this lake. Presence only - no abundance ratings.
Facts and Figures
Waterbody ID56776631
CountyCarbon
Coordinates45.4439, -109.2223
Largest Lakes in Montana
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Fort Peck Lake | Valley | 233,053 acres | - |
| 2 | Flathead Lake | Lake | 122,132 acres | About 380 ft |
| 3 | Canyon Ferry Lake | Broadwater | 32,773 acres | About 170 ft |
| 4 | Lake Koocanusa | Lincoln | 28,723 acres | - |
| 5 | Hungry Horse Reservoir | Flathead | 23,577 acres | - |
Sources: Montana Fish, Wildlife & Parks lake data (ID 56776631). Verified October 30, 2026.