Long Lake vs Town Line Lake
Water quality, depth, fish species, and recreation comparison.
Long Lake has a higher water quality grade (A, Excellent) than Town Line Lake (C, Fair). Both are in Cass County, Minnesota.
Both Long Lake and Town Line 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. Long Lake (A) is materially cleaner than Town Line Lake (C). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.
For a recreational visitor, the wider grade gap is decisive — Long Lake is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Long Lake
Crystal clear, you can see 21.5 ft down.
Town Line Lake
Murky, only visible to about 6.6 ft.
Side-by-Side Metrics
| Metric | Long Lake | Town Line Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 21.5 ft | 6.6 ft |
| Phosphorus | 9 µg/L | 11 µg/L |
| Chlorophyll-a (Algae) | 3 µg/L | 2.1 µg/L |
| Maximum Depth | 115 ft | 11 ft |
| Surface Area | 1,007 acres | 698 acres |
| Public Access | Yes | Yes |
| Fish Species | 14 | 8 |
| Trophic State | oligotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Long Lake wins on overall water quality with a Grade A versus Town Line Lake's Grade C. Water clarity: 21.5 ft vs 6.6 ft. For fishing diversity, Long Lake also leads with 14 species.
Source: EPA National Aquatic Resource Surveys, 2026.