Lakes / Idaho / Custer County / Mackay Reservoir
Mackay Reservoir, Idaho
1,177.96 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Idaho
43.96 degrees N, 113.70 degrees W - Custer 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 Mackay Reservoir Stacks Up
- Larger than 88% of the 316 lakes counted in Idaho.
- About 38 miles from Ketchum, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Nichols Reservoir | Butte | 28 mi | 35.34 acres |
| Campbell Reservoir | Blaine | 37 mi | 106.01 acres |
| Fish Creek Reservoir | Blaine | 37 mi | 244.88 acres |
| Cameron Reservoir | Blaine | 37 mi | 30.15 acres |
| Jimmy Smith Lake | Custer | 38 mi | 62.76 acres |
| Little Wood River Reservoir | Blaine | 39 mi | 578.47 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Mackay Reservoir
How Big Is Mackay Reservoir?
Mackay Reservoir covers 1,177.96 acres in Custer County, Idaho.
What Is the Largest Lake in Custer County?
Redfish Lake is the largest lake in Custer County, at 1,503.88 acres.
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 45094260). Verified October 30, 2026.