Dead Lake vs Marion Lake
Water quality, depth, fish species, and recreation comparison.
Dead Lake has a higher water quality grade (A, Excellent) than Marion Lake (B, Good). Both are in Otter Tail County, Minnesota.
Both Dead Lake and Marion 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: Dead Lake (A) and Marion Lake (B) 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.
Dead Lake
Good clarity, visible to about 10.2 ft.
Marion Lake
Good clarity, visible to about 11 ft.
Side-by-Side Metrics
| Metric | Dead Lake | Marion Lake |
|---|---|---|
| Overall Grade | A (Excellent) | B (Good) |
| Water Clarity | 10.2 ft | 11 ft |
| Phosphorus | 20 µg/L | 18 µg/L |
| Chlorophyll-a (Algae) | 5.8 µg/L | 7.3 µg/L |
| Maximum Depth | 65 ft | 62 ft |
| Surface Area | 7,546 acres | 1,624 acres |
| Public Access | Yes | Yes |
| Fish Species | 18 | 17 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Dead Lake wins on overall water quality with a Grade A versus Marion Lake's Grade B. Water clarity: 10.2 ft vs 11 ft. For fishing diversity, Dead Lake also leads with 18 species.
Source: EPA National Aquatic Resource Surveys, 2026.