Mazaska Lake vs Union Lake
Water quality, depth, fish species, and recreation comparison.
Mazaska Lake reads lower on nutrients and algae than Union Lake. Both are in Rice County, Minnesota.
Both Mazaska Lake and Union 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. These two sit close on their nutrient and algae readings, Mazaska Lake versus Union 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.
Mazaska Lake
Very murky, less than 2.5 ft of visibility.
Union Lake
Very murky, less than 3 ft of visibility.
Side-by-Side Metrics
| Metric | Mazaska Lake | Union Lake |
|---|---|---|
| Water Clarity | 2.5 ft | 3 ft Better |
| Phosphorus | 89 µg/L Better | 375 µg/L |
| Chlorophyll-a (Algae) | 51.3 µg/L | 29.2 µg/L Better |
| Maximum Depth | 50 ft Better | 10 ft |
| Surface Area | 688 acres | 397 acres |
| Public Access | Yes | Yes |
| Fish Species | 17 Better | 0 |
| Trophic State | eutrophic | hypereutrophic |
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
Union Lake reads lower on nutrients and algae than Mazaska Lake. Water clarity: 3 ft vs 2.5 ft. For more fish-species variety, Mazaska Lake edges ahead with 17 documented species.
Stays via Stay22
Where to stay near Mazaska Lake and Union Lake
Compare cabins, hotels, and vacation rentals around Mazaska Lake and Union 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 Mazaska Lake and Union Lake
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Source: EPA National Aquatic Resource Surveys, 2026.