Lakes / Idaho / Valley County / Riordan Lake
Riordan Lake, Idaho
74.38 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Idaho
44.85 degrees N, 115.44 degrees W - Valley 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 Riordan Lake Stacks Up
- Larger than 48% of the 316 lakes counted in Idaho.
- About 93 miles from Boise, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Caton Lake | Valley | 7.5 mi | 39.49 acres |
| Warm Lake | Valley | 18 mi | 422.55 acres |
| Blackmare Lake | Valley | 19 mi | 30.15 acres |
| Buckhorn Lake | Valley | 21 mi | 30.39 acres |
| Boulder Lake | Valley | 25 mi | 90.81 acres |
| Thirtythree Lake | Valley | 25 mi | 39.54 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Riordan Lake
How Big Is Riordan Lake?
Riordan Lake covers 74.38 acres in Valley County, Idaho.
What Is the Largest Lake in Valley County?
Lake Cascade is the largest lake in Valley County, at 25,043.4 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 52919253). Verified October 30, 2026.