Lakes / Oregon / Marion County / Willamette Slough
Willamette Slough, Oregon
55 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Oregon
44.93 degrees N, 123.05 degrees W - Marion 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 Willamette Slough Stacks Up
- Larger than 38% of the 642 lakes counted in Oregon.
- About 1 miles from Salem, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Stone Quarry Lake | Marion | 2.2 mi | 42 acres |
| Clear Lake | Marion | 6.8 mi | 37 acres |
| Mission Lake | Marion | 10 mi | 29 acres |
| Morgan Lake | Polk | 11 mi | 50 acres |
| Lambert Slough | Yamhill | 15 mi | 117 acres |
| Lillie Walker Irrigation Pond | Polk | 15 mi | 29 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Willamette Slough
How Big Is Willamette Slough?
Willamette Slough covers 55 acres in Marion County, Oregon.
What Is the Largest Lake in Marion County?
Detroit Lake is the largest lake in Marion County, at 3,593 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 147816010). Verified October 30, 2026.