Osage County Lake Quality
Oklahoma, 13 lakes, average grade D (Poor)
Only 13 lakes in Osage County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. On average, Osage County lakes grade D, with phosphorus loading and reduced clarity showing up across most of the dataset.
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 Nla Lake (B); the most-stressed is Nla Lake (D).
Quick Answers for Osage County
Planning a trip? Check special fishing regulations for Nla Lake — or check the official Oklahoma fishing regulations.
All Lakes in Osage County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Nla Lake | B | 4.8 ft | 30.7 µg/L |
| 2 | Nla Lake | C | 3.3 ft | 26.4 µg/L |
| 3 | Nla Lake | C | 7.2 ft | 24000 µg/L |
| 4 | Nla Lake | C | 1.8 ft | 15017.3 µg/L |
| 5 | Nla Lake | D | 0.7 ft | 87000 µg/L |
| 6 | Nla Lake | D | 2.9 ft | 15018.4 µg/L |
| 7 | Nla Lake | D | 4.8 ft | 2506 µg/L |
| 8 | Sandy Beach Lake | D | - | 308.5 µg/L |
| 9 | Osage Cove Lake | D | - | 222 µg/L |
| 10 | Pioneer Cover Lake | D | - | 227 µg/L |
| 11 | Nla Lake | D | 0.5 ft | 132.7 µg/L |
Other Counties in Oklahoma
See how Osage County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 34 states.
Where to stay near Osage County
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Source: EPA National Aquatic Resource Surveys, 2026.