Deer Yard Lake
Deer Yard Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Water clarity: 7.2 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 5.3 µg/L. Maximum depth: 20 ft. Surface area: 342.87 acres.
- Clarity
- 7.2 ft
- Max depth
- 20 ft
- Area
- 343 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- May 14
Next lake in Cook County
Deer Yard Lake is a 343-acre mesotrophic lake in Cook County, Minnesota with a maximum depth of 20 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 2 documented fish species including walleye and white sucker. Public access is available. Compared to the 43 other monitored lakes in Cook County, Deer Yard Lake ranks #12 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-08-17. 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)
Moderate clarity, visible to about 7.2 ft. Phosphorus level: 15 µg/L. Chlorophyll-a: 5.3 µg/L. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.2 ft | Not graded |
| Phosphorus | 15 µg/L | Good |
| Chlorophyll-a (Algae) | 5.3 µg/L | Good |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Deer Yard Lake
Compare lakeside cabins, hotels, and vacation rentals near Deer Yard Lake in Cook 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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Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Deer Yard Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (366,438 cells/mL) on May 30, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 20 ft |
| Surface Area | 343 acres |
| Shoreline Length | 5.1 mi |
| Littoral Zone | 58% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Deer Yard Lake
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2018-08-10 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Walleye | 17.17 | 0.51 lb |
| White Sucker | 9.72 | 1.87 lb |
| GOS | 2.48 | 0.06 lb |
| CRC | 2.42 | 0.15 lb |
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.
Walleye
White Sucker
GOS
CRC
From the 2018-08-10 survey
Deer Yard Lake has long been known for supporting very high numbers of small Walleye, with no panfish and no other gamefish species present. The current (2012) lake management plan set goals for Walleye of maintaining a high gill net catch (20 fish/set), with a mean weight for fish taken in gill nets of at least 0.7…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Deer Yard Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Deer YardFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Deer Yard (1798)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — Deer YardPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.045 m/yr | 5 |
| Phosphorus | ↓ Declining | +0.66 µg/L/yr | 5 |
| Chlorophyll-a | → Stable | -0.03 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (5 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2020-05-04 (2020) | 2022-05-14 (2022) |
| Ice-In | 2021-11-22 (2021) | 2021-11-22 (2021) |
Most recent ice-out: 2022-05-14
EPA Impairment Status
Deer Yard 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 MN16-0253-00 · Official waterbody report
County Ranking
Ranked #12 of 44 lakes in Cook County
Nearby Lakes in Cook County
Frequently asked questions about Deer Yard Lake
What is the water quality grade for Deer Yard Lake?
- Deer Yard Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Water clarity: 7.2 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 5.3 µg/L. Maximum depth: 20 ft. Surface area: 342.87 acres.
Is Deer Yard Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Deer Yard Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 5.3 µg/L. Always check local health department advisories before swimming.
How deep is Deer Yard Lake?
- Deer Yard Lake has a maximum depth of 20 feet. The lake covers 342.87 acres.
What fish are in Deer Yard Lake?
- Fish species found in Deer Yard Lake include walleye, white sucker. Deer Yard Lake is located in Cook County, Minnesota.
When does Deer Yard Lake thaw?
- Deer Yard Lake typically has ice-out around May 14.
Does Deer Yard Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Deer Yard Lake (clouds, ice, or an off-season gap). The most recent reading was high (366,438 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Deer Yard Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
4 mi away · 30 ft
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Species activity outlook by water temperature and season
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Where this data comes from
76 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
MNPCA76 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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
Ice data from Minnesota DNR Climate