Upper Hay Lake
Upper Hay Lake in Crow Wing County, Minnesota has a water quality grade of A (Excellent). 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.
- Clarity
- 10.9 ft
- Typical in August
- 69°F
- Max depth
- 42 ft
- Area
- 596 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 12
Next lake in Crow Wing County
Upper Hay Lake is a 596-acre mesotrophic lake in Crow Wing County, Minnesota with a maximum depth of 42 feet. Water quality is graded A based on 2 sampling years through 2025. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
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 10.9 ft. Phosphorus level: 20 µg/L. Chlorophyll-a: 4.8 µg/L. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.9 ft | Not graded |
| Phosphorus | 20 µg/L | Good |
| Chlorophyll-a (Algae) | 4.8 µg/L | Good |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Upper Hay Lake
Compare lakeside cabins, hotels, and vacation rentals near Upper Hay Lake in Crow Wing 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
Upper Hay Lake typically sits around 69°F at the surface in August. 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.
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 →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 42 ft |
| Surface Area | 596 acres |
| Shoreline Length | 3.8 mi |
| Littoral Zone | 35% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Upper Hay LakePublic
Fish Species
Click a species to see every graded 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.
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2022-06-27 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluntnose Minnow | 20.23 | — |
| MMS | 14.87 | — |
| Bluegill | 14.79 | 0.19 lb |
| Yellow Perch | 14.32 | 0.11 lb |
| JND | 8.64 | — |
| BKF | 7.83 | — |
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
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
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.33 m/yr | 6 |
| Phosphorus | → Stable | -0.04 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -1.17 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (4 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2015-04-06 (2015) | 2013-05-10 (2013) |
| Ice-In | 2004-12-20 (2004) | 2004-12-20 (2004) |
Most recent ice-out: 2015-04-06
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN18-0412-00 · Official waterbody report
County Ranking
Ranked #47 of 85 lakes in Crow Wing County
Nearby Lakes in Crow Wing County
Frequently asked questions about Upper Hay Lake
What is the water quality grade for Upper Hay Lake?
- Upper Hay Lake in Crow Wing County, Minnesota has a water quality grade of A (Excellent). 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?
- Excellent for swimming, crystal clear water with minimal algae. Upper Hay Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Upper Hay Lake?
- Upper Hay Lake typically sits around 69°F at the surface in August, 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.
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.
Explore Upper Hay Lake across LakeGrade
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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)
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
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