Johnson Lake vs Trout Lake
Water quality, depth, fish species, and recreation comparison.
Johnson Lake and Trout Lake both received the same overall water quality grade of A (Excellent). Both are in Itasca County, Minnesota.
Both Johnson Lake and Trout Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. The grades are close: Johnson Lake (A) and Trout Lake (A) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Johnson Lake
Crystal clear, you can see 15.7 ft down.
Trout Lake
Crystal clear, you can see 18 ft down.
Side-by-Side Metrics
| Metric | Johnson Lake | Trout Lake |
|---|---|---|
| Overall Grade | A (Excellent) | A (Excellent) |
| Water Clarity | 15.7 ft | 18 ft |
| Phosphorus | 9.5 µg/L | 3.5 µg/L |
| Chlorophyll-a (Algae) | 2.7 µg/L | 1.1 µg/L |
| Maximum Depth | 88 ft | 157 ft |
| Surface Area | 434 acres | 1,743 acres |
| Public Access | Yes | No |
| Fish Species | 11 | 9 |
| Trophic State | oligotrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Johnson Lake: 15.7 ft, Trout Lake: 18 ft) and what you want from the lake. Johnson Lake supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.