Big Lake vs Sturgeon Lake
Water quality, depth, fish species, and recreation comparison.
Big Lake and Sturgeon Lake read the same on nutrients and algae. Both are in St. Louis County, Minnesota.
Big Lake and Sturgeon Lake are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. These two sit close on the readings, Big Lake versus Sturgeon Lake. The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
With readings 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.
Big Lake
Moderate clarity, visible to about 8.2 ft.
Sturgeon Lake
Good clarity, visible to about 13.8 ft.
Side-by-Side Metrics
| Metric | Big Lake | Sturgeon Lake |
|---|---|---|
| Water Clarity | 8.2 ft | 13.8 ft Better |
| Phosphorus | 14 µg/L | 12.5 µg/L Better |
| Chlorophyll-a (Algae) | 4.9 µg/L | 2.7 µg/L Better |
| Maximum Depth | 22 ft | 79.8 ft Better |
| Surface Area | 1,904 acres | 1,585 acres |
| Public Access | Yes | Yes |
| Fish Species | 8 | 15 Better |
| Trophic State | mesotrophic | mesotrophic |
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.
Swap a lake
Compare Big Lake or Sturgeon Lake against a different lake.
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Big Lake: 8.2 ft, Sturgeon Lake: 13.8 ft) and what you want from the lake. Big Lake has fewer fish species than Sturgeon Lake.
Source: EPA National Aquatic Resource Surveys, 2026.