Birch Lake vs Girl Lake
Water quality, depth, fish species, and recreation comparison.
Girl Lake reads lower on nutrients and algae than Birch Lake. Both are in Cass County, Minnesota.
Birch Lake and Girl 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 their nutrient and algae readings, Birch Lake versus Girl 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.
Birch Lake
Good clarity, visible to about 14 ft.
Girl Lake
Crystal clear, you can see 17.6 ft down.
Side-by-Side Metrics
| Metric | Birch Lake | Girl Lake |
|---|---|---|
| Water Clarity | 14 ft | 17.6 ft Better |
| Phosphorus | 12 µg/L | 12 µg/L |
| Chlorophyll-a (Algae) | 4 µg/L | 2.7 µg/L Better |
| Maximum Depth | 45 ft | 81 ft Better |
| Surface Area | 1,267 acres | 428 acres |
| Public Access | Yes | Yes |
| Fish Species | 14 | 18 Better |
| Trophic State | mesotrophic | oligotrophic |
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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Verdict
Birch Lake and Girl Lake read the same on nutrients and algae overall. The tiebreakers come down to clarity (Birch Lake: 14 ft, Girl Lake: 17.6 ft) and what you want from the lake. Birch Lake has fewer fish species than Girl Lake.
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Where to stay near Birch Lake and Girl Lake
Compare cabins, hotels, and vacation rentals around Birch Lake and Girl Lake. Both lakes are pinned on the map, so you can see which stays sit nearer the one you pick. Switch to Satellite to see how close each is to the water.
Top-rated places to stay near Birch Lake and Girl Lake
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Source: EPA National Aquatic Resource Surveys, 2026.