Mountrail County Lake Quality
North Dakota, 5 lakes, average grade C (Fair)
Mountrail County has 5 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 average is C — the middle of the rubric, with one or two lakes pulling the average up or down depending on year.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Powers Lake (C) is the cleanest in the county.
Quick Answers for Mountrail County
Planning a trip? Check special fishing regulations for Powers Lake, whether the fish are safe to eat, and the best times to fish — or check the official North Dakota fishing regulations.
Fishing in Mountrail County
All Lakes in Mountrail County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Powers Lake | C | 5.6 ft | 9.7 ft | - |
| 2 | White Earth Dam Lake | C | 3 ft | 19.5 ft | - |
| 3 | Clearwater Lake | C | 2.1 ft | 16.5 ft | - |
| 4 | Powers Lake Dredge Site | C | 3.9 ft | 9.7 ft | - |
| 5 | Stanley Reservoir | D | 1.1 ft | 22.5 ft | - |
Other Counties in North Dakota
See how Mountrail County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 15 states.
Where to stay near Mountrail County
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Source: EPA National Aquatic Resource Surveys, 2026.