Hay Lake
Hay Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13.2 ft visibility. Phosphorus: 16.5 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 56 ft. Surface area: 363.7 acres.
- Clarity
- 13.2 ft
- Typical in August
- 60°F
- Max depth
- 56 ft
- Area
- 364 acres
- Type
- Mesotrophic
- Public access
- Yes
Next lake in Cass County
Hay Lake is a 364-acre mesotrophic lake in Cass County, Minnesota with a maximum depth of 56 feet. Water quality is graded A based on 2 sampling years through 2023. The lake supports 14 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 103 other monitored lakes in Cass County, Hay Lake ranks #67 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-09-06. Grade methodology: LakeGrade methodology.
Watch Hay Lake water quality
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 13.2 ft. Phosphorus level: 16.5 µg/L. Chlorophyll-a: 2.4 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 13.2 ft | Not graded |
| Phosphorus | 16.5 µg/L | Good |
| Chlorophyll-a (Algae) | 2.4 µg/L | Good |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Hay Lake
Compare lakeside cabins, hotels, and vacation rentals near Hay Lake in Cass County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Water Temperature
Hay Lake typically sits around 60°F at the surface in August. Summer average is about 59°F. Usually warmest in Aug (about 60°F) and coldest in May (about 49°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 127 field readings (2011–2024) via the EPA Water Quality Portal. See the full Hay Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 56 ft |
| Surface Area | 364 acres |
| Shoreline Length | 5.2 mi |
| Littoral Zone | 49% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Hay LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Hay Lake
DNR Fisheries Survey Summary
14 surveys on file from MN DNR Fisheries. Most recent: 2024-08-01 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 22.16 | 0.19 lb |
| Bluntnose Minnow | 19.80 | — |
| GOS | 14.65 | — |
| BCS | 10.32 | — |
| BNS | 9.60 | — |
| Spottail Shiner | 6.89 | — |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
From the 2024-08-01 survey
Temperature and dissolved oxygen profiles were collected in the deepest basins in Hay Lake on August 1, 2024 , to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. Cisco require a…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Hay Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — HayFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Hay (1527)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — HayFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — HayPublic Water Access Sites · MN DNR LakeFinder
County Ranking
Ranked #67 of 104 lakes in Cass County
Nearby Lakes in Cass County
Frequently asked questions about Hay Lake
What is the water quality grade for Hay Lake?
- Hay Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13.2 ft visibility. Phosphorus: 16.5 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 56 ft. Surface area: 363.7 acres.
Is Hay Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Hay Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2.4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Hay Lake?
- Hay Lake typically sits around 60°F at the surface in August, from 127 EPA Water Quality Portal field readings (2011–2024). That is a typical value for the month, not a live reading.
How deep is Hay Lake?
- Hay Lake has a maximum depth of 56 feet. The lake covers 363.7 acres.
What fish are in Hay Lake?
- Fish species found in Hay Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, yellow bullhead, yellow perch. Hay Lake is located in Cass County, Minnesota.
Are there boat ramps on Hay Lake?
- Hay Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Hay Lake. Public access is listed as yes.
Explore Hay Lake across LakeGrade
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Where this data comes from
20 measurements from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA20 samples · 2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory