Columbia County Lake Quality
Oregon, 1 lakes, average grade (Not rated)
Columbia County has 1 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Scout Lake (—); the most-stressed is Scout Lake (—).
Quick Answers for Columbia County
Planning a trip? Check special fishing regulations for Scout Lake — or check the official Oregon fishing regulations.
All Lakes in Columbia County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Scout Lake | - | 45 µg/L |
Other Counties in Oregon
See how Columbia County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 36 states and 2 Canadian provinces.
Where to stay near Columbia County
Top-rated places to stay near Columbia County
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Source: EPA National Aquatic Resource Surveys, 2026.