Lakes / Oklahoma / Washington County / Copan Lake
Copan Lake, Oklahoma
4,054.44 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Oklahoma
36.93 degrees N, 95.95 degrees W - Washington 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 Copan Lake Stacks Up
- Larger than 92% of the 376 lakes counted in Oklahoma.
- The largest lake in Washington County among those counted.
- About 54 miles from Tulsa, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Youngs Lake | Washington | 3.7 mi | 55.85 acres |
| Long Lake | Washington | 4.7 mi | 29.16 acres |
| Bar-Dew Lake | Osage | 7.9 mi | 34.84 acres |
| Lake Hudson | Osage | 9.2 mi | 268.28 acres |
| Sunset Lake | Osage | 18 mi | 65.78 acres |
| Chouteau Lake | Nowata | 20 mi | 25.45 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Copan Lake
How Big Is Copan Lake?
Copan Lake covers 4,054.44 acres in Washington County, Oklahoma.
What Is the Largest Lake in Washington County?
Copan Lake is the largest lake in Washington County, at 4,054.44 acres.
Largest Lakes in Oklahoma
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Eufaula Lake | Pittsburg | 100,734.12 acres | - |
| 2 | Lake Texoma | Marshall | 59,414.43 acres | - |
| 3 | Grand Lake O' The Cherokees | Delaware | 38,902.36 acres | - |
| 4 | Robert S Kerr Reservoir | Haskell | 35,795.91 acres | - |
| 5 | Oologah Lake | Rogers | 29,728.7 acres | - |
All 376 Oklahoma lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 131493834). Verified October 30, 2026.