Bear Island Lake vs Big Lake
Water quality, depth, fish species, and recreation comparison.
Bear Island Lake and Big Lake both received the same overall water quality grade of A (Excellent). Both are in St. Louis County, Minnesota.
Bear Island Lake and Big 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 are within a letter of each other on the rubric — Bear Island Lake (A) versus Big Lake (A). 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.
Bear Island Lake
Moderate clarity, visible to about 7 ft.
Big Lake
Moderate clarity, visible to about 8.2 ft.
Side-by-Side Metrics
| Metric | Bear Island Lake | Big Lake |
|---|---|---|
| Overall Grade | A (Excellent) | A (Excellent) |
| Water Clarity | 7 ft | 8.2 ft |
| Phosphorus | 15 µg/L | 14 µg/L |
| Chlorophyll-a (Algae) | 6.4 µg/L | 4.9 µg/L |
| Maximum Depth | 62 ft | 22 ft |
| Surface Area | 2,362 acres | 1,904 acres |
| Public Access | Yes | Yes |
| Fish Species | 13 | 8 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Bear Island Lake: 7 ft, Big Lake: 8.2 ft) and what you want from the lake. Bear Island Lake supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.