Upper Hay Lake
Crow Wing County, Minnesota596 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Upper Hay Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- zebra mussel
- 42 ft max depth
- Public access
Upper Hay Lake in Crow Wing County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.9 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 4.8 µg/L. Maximum depth: 42 ft. Surface area: 595.7 acres.
Minnesota DNR's Targeted Survey on June 27, 2022 caught 0.11 walleye per trap net at Upper Hay Lake. DNR survey details →
Upper Hay Lake is a 596-acre mesotrophic lake in Crow Wing County, Minnesota with a maximum depth of 42 feet. Overall water quality is improving over recent sampling years. The lake supports 13 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 1 public boat landing. Compared to the 84 other monitored lakes in Crow Wing County, Upper Hay Lake ranks #47 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-14. Methodology: how these readings are compared.
What Upper Hay Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10.9 ft of visibility
- Boat launch1 documented ramp
- Fishing13 species recorded
- Ice seasonIce-out around Apr 12
- Deep water42 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Upper Hay Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Upper Hay Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Upper Hay Lake
These are the measurements Minnesota PCA publishes for Upper Hay Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10.9 ft. Phosphorus 20 µg/L. Chlorophyll-a 4.8 µg/L. TSI 45.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4.8µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 45 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Upper Hay Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Upper Hay Lake typically sits around 67°F at the surface in September. Summer average is about 68°F. Usually warmest in Jul (about 69°F) and coldest in May (about 57°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (57°F) to its warmest (69°F).
Typical surface water temperature by month, from 196 field readings (2017–2025) via the EPA Water Quality Portal. See the full Upper Hay Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on June 27, 2022 caught 0.11 walleye per trap net at Upper Hay Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Upper Hay Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2022-06-27 (Targeted Survey).
10 surveys on file · most recent 2022-06-27 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluntnose Minnow | 20.23 | ||
| Bluegill | 14.79 | 1–9 in 2022-06-27 | 0.19 lb |
| Yellow Perch | 14.32 | 4–8 in 2022-06-27 | 0.11 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Yellow Perch
From the 2022-06-27 survey
A targeted survey of nearshore fish species in Upper Hay Lake was conducted on June 27-29, 2022, by Index of Biological Integrity (IBI) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Upper Hay Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Upper HayFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — Upper HayFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Upper HayPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
42 ft
Surface area
596 acres
Shoreline
3.8 mi
Littoral zone
35%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
9 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,220 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Upper Hay LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Upper Hay Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Upper Hay Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Stable-0.04 µg/L/yr6 years
Chlorophyll-a
Improving-1.17 µg/L/yr6 years
Ice season
Typical ice-out
Apr 12
Earliest Apr 6, 2015 · Latest May 10, 2013
Most recent ice-out
Apr 6
2015
4 observations · Minnesota PCA ice records
EPA Impairment Status
Upper Hay Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN18-0412-00 · Official waterbody report
Nearby Lakes in Crow Wing County
Frequently asked questions about Upper Hay Lake
Where is Upper Hay Lake?
- Upper Hay Lake is a lake in Crow Wing County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Upper Hay Lake?
- Upper Hay Lake in Crow Wing County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.9 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 4.8 µg/L. Maximum depth: 42 ft. Surface area: 595.7 acres.
Is Upper Hay Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Upper Hay Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Upper Hay Lake?
- Upper Hay Lake typically sits around 67°F at the surface in September, from 196 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
How deep is Upper Hay Lake?
- Upper Hay Lake has a maximum depth of 42 feet. The lake covers 595.7 acres.
What fish are in Upper Hay Lake?
- Fish species found in Upper Hay Lake include black crappie, bluegill, bowfin (dogfish), green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow bullhead, yellow perch. Upper Hay Lake is located in Crow Wing County, Minnesota.
What did the DNR fisheries survey find at Upper Hay Lake?
- Minnesota DNR's Targeted Survey on June 27, 2022 caught 0.11 walleye per trap net at Upper Hay Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Upper Hay Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Upper Hay Lake thaw?
- Upper Hay Lake typically has ice-out around Apr 12.
Are there boat ramps on Upper Hay Lake?
- Upper Hay Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Upper Hay Lake. Public access is listed as yes.
Can I fish at Upper Hay Lake?
- Upper Hay Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Upper Hay Lake across LakeQuality
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Where this data comes from
172 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA172 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (2)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate