Lakes / Idaho / Power County / American Falls Reservoir
American Falls Reservoir, Idaho
55,319.78 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Idaho
42.92 degrees N, 112.77 degrees W - Power 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 American Falls Reservoir Stacks Up
- Ranks #2 for surface area among the Idaho lakes counted so far - 55,319.78 acres.
- The largest lake in Power County among those counted.
- About 54 miles from Idaho Falls, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Big Fill Reservoir | Bingham | 12 mi | 39.53 acres |
| Bonanza Lake | Power | 21 mi | 30.64 acres |
| Jensens Lake | Bingham | 29 mi | 57.82 acres |
| Equalizing Reservoir | Bingham | 30 mi | 230.3 acres |
| Lake Walcott | Cassia | 33 mi | 11,782.92 acres |
| Hawkins Reservoir | Bannock | 36 mi | 49.63 acres |
Straight-line distance between lake centers.
Facts and Figures
Largest Lakes in Idaho
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Lake Pend Oreille | Bonner | 92,764.44 acres | - |
| 2 | American Falls Reservoir | Power | 55,319.78 acres | - |
| 3 | Coeur d'Alene Lake | Kootenai | 26,891.64 acres | - |
| 4 | Lake Cascade | Valley | 25,043.4 acres | - |
| 5 | Priest Lake | Bonner | 23,425.59 acres | - |
All 316 Idaho lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 56466309). Verified October 30, 2026.