Greenwood Lake
Cook County, Minnesota2,043 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Greenwood Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- spiny waterflea
- 112 ft max depth
- Public access
Greenwood Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 15.1 ft visibility. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 2.6 µg/L. Maximum depth: 112 ft. Surface area: 2042.66 acres.
Minnesota DNR's Targeted Survey on August 11, 2025 caught 8.90 smallmouth bass per hour of electrofishing at Greenwood Lake. Length samples in the latest survey that recorded them ran 7–13 inches. DNR survey details →
Free interactive depth-contour map of Greenwood Lake, reaching a maximum surveyed depth of 100 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Greenwood Lake is a 2,043-acre cold, clear oligotrophic lake in Cook County, Minnesota with a maximum depth of 112 feet. Overall water quality is improving over recent sampling years. The lake supports 10 documented fish species including brook trout, cisco species, and green sunfish. Public access is available with 1 public boat landing. Compared to the 43 other monitored lakes in Cook County, Greenwood Lake ranks #29 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-08. Methodology: how these readings are compared.
Greenwood Lake covers about 2,000 acres in Cook County. It has one public boat landing. The median ice-out date is May 8, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Greenwood Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Greenwood Lake is good for
From access and monitoring records, not editorial picks.
- Clear water15.1 ft of visibility
- Boat launch1 documented ramp
- Fishing10 species recorded
- Ice seasonIce-out around May 8
- Deep water112 ft surveyed max depth
- Big water2,043 acres
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. Greenwood Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Greenwood 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 Greenwood Lake
These are the measurements Minnesota PCA publishes for Greenwood Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 15.1 ft down. Phosphorus 10 µg/L. Chlorophyll-a 2.6 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 15.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.6µg/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. | 38 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Greenwood Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Greenwood Lake typically sits around 49°F at the surface in October. Summer average is about 52°F. Usually warmest in Aug (about 54°F) and coldest in May (about 44°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (44°F) to its warmest (54°F).
Typical surface water temperature by month, from 1,200 field readings (2018–2025) via the EPA Water Quality Portal. See the full Greenwood Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on August 11, 2025 caught 8.90 smallmouth bass per hour of electrofishing at Greenwood Lake. Length samples in the latest survey that recorded them ran 7–13 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Greenwood Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
14 surveys on file from MN DNR Fisheries. Most recent: 2025-08-11 (Targeted Survey).
14 surveys on file · most recent 2025-08-11 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Tullibee (Cisco) | 8.99 | 8–18 in 2009-08-17 | 0.82 lb |
| Lake Trout | 2.77 | 9–28 in 2022-08-22 | 1.43 lb |
| White Sucker | 2.48 | 17–21 in 2022-08-22 | 2.17 lb |
| Smallmouth Bass | 1.68 | 7–13 in 2022-08-22 | 0.55 lb |
| Green Sunfish | 1.54 | 5 in 2022-08-22 | 0.09 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.
Tullibee (Cisco)
Lake Trout
White Sucker
Smallmouth Bass
From the 2025-08-11 survey
A targeted survey of nearshore fish species in Greenwood Lake was conducted on August 11-14, 2025, by Lake Biological Monitoring and Assessment Program staff. Nearshore sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing, mini-fyke nets, and seining with a 50-foot or…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Greenwood Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — GreenwoodFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Greenwood (1824)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — GreenwoodPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
112 ft
Surface area
2,043 acres
Shoreline
23.4 mi
Littoral zone
26%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
12 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,867 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Greenwood 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 Greenwood Lake
Compare lakeside cabins, hotels, and vacation rentals near Greenwood 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.
Top-rated places to stay near Greenwood Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Greenwood Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Greenwood 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 4 years of monitoring (2021–2025).
Water clarity
Stable4 years
Phosphorus
Stable-0.11 µg/L/yr4 years
Chlorophyll-a
Improving-0.31 µg/L/yr4 years
Ice season
Typical ice-out
May 8
Earliest Apr 10, 2012 · Latest May 24, 2014
Typical ice-in
Dec 3
Earliest Nov 29, 2023 · Latest Dec 5, 2024
Most recent ice-out
Apr 27
2024
25 observations · Minnesota PCA ice records
EPA Impairment Status
Greenwood 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 MN16-0077-00 · Official waterbody report
Nearby Lakes in Cook County
Frequently asked questions about Greenwood Lake
Where is Greenwood Lake?
- Greenwood Lake is a lake in Cook County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Greenwood Lake?
- Greenwood Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 15.1 ft visibility. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 2.6 µg/L. Maximum depth: 112 ft. Surface area: 2042.66 acres.
Is Greenwood Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Greenwood 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 Greenwood Lake?
- Greenwood Lake typically sits around 49°F at the surface in October, from 1,200 EPA Water Quality Portal field readings (2018–2025). That is a typical value for the month, not a live reading.
How deep is Greenwood Lake?
- Greenwood Lake has a maximum depth of 112 feet. The lake covers 2042.66 acres.
What fish are in Greenwood Lake?
- Fish species found in Greenwood Lake include brook trout, cisco species, green sunfish, lake trout, lake whitefish, northern pike, smallmouth bass, tullibee (cisco), white sucker, yellow perch. Greenwood Lake is located in Cook County, Minnesota.
What did the DNR fisheries survey find at Greenwood Lake?
- Minnesota DNR's Targeted Survey on August 11, 2025 caught 8.90 smallmouth bass per hour of electrofishing at Greenwood Lake. Length samples in the latest survey that recorded them ran 7–13 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Greenwood Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Greenwood Lake thaw?
- Greenwood Lake typically has ice-out around May 8. Ice typically forms around Dec 3. The open water season is approximately 209 days.
Are there boat ramps on Greenwood Lake?
- Greenwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Greenwood Lake. Public access is listed as yes.
Can I fish at Greenwood Lake?
- Greenwood 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 Greenwood Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Cook County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Greenwood Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Compare Greenwood Lake With Nearby Lakes
Where this data comes from
81 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA81 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
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