Lower Hay Lake vs Upper Hay Lake
Water quality, depth, fish species, and recreation comparison.
Lower Hay Lake and Upper Hay Lake read the same on nutrients and algae. Both are in Crow Wing County, Minnesota.
Both Lower Hay Lake and Upper Hay 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. The readings are close: Lower Hay Lake and Upper Hay Lake sit within a narrow band of each other on phosphorus, chlorophyll-a and clarity. The per-parameter table below shows where the small differences actually live.
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.
Lower Hay Lake
Crystal clear, you can see 18.5 ft down.
Upper Hay Lake
Good clarity, visible to about 10.9 ft.
Side-by-Side Metrics
| Metric | Lower Hay Lake | Upper Hay Lake |
|---|---|---|
| Water Clarity | 18.5 ft Better | 10.9 ft |
| Phosphorus | 13 µg/L Better | 20 µg/L |
| Chlorophyll-a (Algae) | 2.7 µg/L Better | 4.8 µg/L |
| Maximum Depth | 100 ft Better | 42 ft |
| Surface Area | 700 acres | 596 acres |
| Public Access | Yes | Yes |
| Fish Species | 21 Better | 13 |
| Trophic State | oligotrophic | 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 Lower Hay Lake or Upper Hay Lake against a different lake.
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Lower Hay Lake: 18.5 ft, Upper Hay Lake: 10.9 ft) and what you want from the lake. Lower Hay Lake supports more documented fish species.
Source: EPA National Aquatic Resource Surveys, 2026.