Lakes / Oregon / Klamath County / Twenty One Reservoir
Twenty One Reservoir, Oregon
30 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Oregon
42.09 degrees N, 121.06 degrees W - Klamath 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 Twenty One Reservoir Stacks Up
- Larger than 10% of the 642 lakes counted in Oregon.
- About 94 miles from Medford, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Gerber Lower Division Reservoir | Klamath | 1.0 mi | 31 acres |
| Upper Midway Reservoir | Klamath | 2.6 mi | 49 acres |
| Antelope Reservoir | Klamath | 3.2 mi | 150 acres |
| Dog Hollow Reservoir | Klamath | 3.2 mi | 45 acres |
| Bumphead Reservoir | Klamath | 3.3 mi | 43 acres |
| Round Valley Reservoir | Klamath | 3.5 mi | 311 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Twenty One Reservoir
How Big Is Twenty One Reservoir?
Twenty One Reservoir covers 30 acres in Klamath County, Oregon.
What Is the Largest Lake in Klamath County?
Upper Klamath Lake is the largest lake in Klamath County, at 62,095 acres.
Largest Lakes in Oregon
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Upper Klamath Lake | Klamath | 62,095 acres | - |
| 2 | Lake Umatilla | Morrow | 50,042 acres | - |
| 3 | Lake Abert | Lake | 37,137 acres | - |
| 4 | Summer Lake | Lake | 31,602 acres | - |
| 5 | Harney Lake | Harney | 31,290 acres | - |
All 642 Oregon lakes ranked by surface area
Sources: USGS NHD (The National Map NHD MapServer layer 12) named waterbodies FTYPE 390/436; counties via Census point-in-polygon lake data (ID 84069861). Verified October 30, 2026.