Crook County Lake Quality
Oregon, 3 lakes, average grade C (Fair)
Crook County has 3 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. Crook County averages to a C. The distribution behind that average matters more than the letter: a few stressed lakes versus many decent ones can produce the same average as the inverse.
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 Prineville Reservoir (B); the most-stressed is Prineville Reservoir (B).
Quick Answers for Crook County
Planning a trip? Check special fishing regulations for Prineville Reservoir — or check the official Oregon fishing regulations.
All Lakes in Crook County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Prineville Reservoir | B | - | - |
Other Counties in Oregon
See how Crook County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 27 states.
Where to stay near Crook County
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Source: EPA National Aquatic Resource Surveys, 2026.