Marion Lake vs Preston Lake
Water quality, depth, fish species, and recreation comparison.
Marion Lake has a higher water quality grade (D, Poor) than Preston Lake (F, Very Poor). Both are in Minnesota.
Both Marion Lake and Preston 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. These two are within a letter of each other on the rubric — Marion Lake (D) versus Preston Lake (F). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
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.
Marion Lake
No clarity data.
Preston Lake
Murky, only visible to about 5 ft.
Side-by-Side Metrics
| Metric | Marion Lake | Preston Lake |
|---|---|---|
| Overall Grade | D (Poor) | F (Very Poor) |
| Water Clarity | No data | 5 ft |
| Phosphorus | 71 µg/L | 222 µg/L |
| Chlorophyll-a (Algae) | No data | 44.1 µg/L |
| Maximum Depth | 15.2 ft | 11 ft |
| Surface Area | 520.43 acres | 654.96 acres |
| Public Access | Yes | Yes |
| Fish Species | 1 | 1 |
| Trophic State | eutrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Marion Lake wins on overall water quality with a Grade D versus Preston Lake's Grade F. For fishing diversity, Marion Lake also leads with 1 species.