Big Lake vs Little Turtle Lake
Water quality, depth, fish species, and recreation comparison.
Big Lake reads lower on nutrients and algae than Little Turtle Lake. Both are in Beltrami County, Minnesota.
Both Big Lake and Little Turtle Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any differences in the readings here are about the lakes themselves, not the agencies sampling them. Big Lake reads materially cleaner than Little Turtle Lake on nutrients and algae. 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 gap in the readings is decisive: Big Lake has the lower nutrient and algae numbers. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Big Lake
Moderate clarity, visible to about 9.7 ft.
Little Turtle Lake
Murky, only visible to about 6.5 ft.
Side-by-Side Metrics
| Metric | Big Lake | Little Turtle Lake |
|---|---|---|
| Water Clarity | 9.7 ft Better | 6.5 ft |
| Phosphorus | 15 µg/L Better | 23.5 µg/L |
| Chlorophyll-a (Algae) | 4.8 µg/L Better | 12 µg/L |
| Maximum Depth | 35 ft Better | 25 ft |
| Surface Area | 3,598 acres | 469 acres |
| Public Access | Yes | No |
| Fish Species | 17 Better | 15 |
| Trophic State | mesotrophic | eutrophic |
A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.
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Compare Big Lake or Little Turtle Lake against a different lake.
Verdict
Big Lake reads lower on nutrients and algae than Little Turtle Lake. Water clarity: 9.7 ft vs 6.5 ft. For fishing diversity, Big Lake also leads with 17 species.
Source: EPA National Aquatic Resource Surveys, 2026.