Big Cormorant Lake
Becker County, Minnesota3,657 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Big Cormorant Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- zebra mussel
- 75 ft max depth
- Public access
Big Cormorant Lake in Becker County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 24.8 ft visibility. Phosphorus: 16.5 µg/L. Chlorophyll-a (algae): 2.2 µg/L. Maximum depth: 75 ft. Surface area: 3657.12 acres.
Minnesota DNR's Targeted Survey on August 25, 2025 caught 14.42 walleye per gill net at Big Cormorant Lake. Length samples in the latest survey that recorded them ran 7–23 inches. DNR survey details →
Free interactive depth-contour map of Big Cormorant Lake, reaching a maximum surveyed depth of 70 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Big Cormorant Lake is a 3,657-acre cold, clear oligotrophic lake in Becker County, Minnesota with a maximum depth of 75 feet. Overall water quality is declining over recent sampling years. The lake supports 16 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 83 other monitored lakes in Becker County, Big Cormorant Lake ranks #25 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Methodology: how these readings are compared.
Big Cormorant Lake covers about 3,700 acres in Becker County. It has one public boat landing. The median ice-out date is April 19, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Big Cormorant Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Big Cormorant Lake is good for
From access and monitoring records, not editorial picks.
- Clear water24.8 ft of visibility
- Boat launch1 documented ramp
- Fishing16 species recorded
- Ice seasonIce-out around Apr 19
- Deep water75 ft surveyed max depth
- Big water3,657 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. Big Cormorant Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Big Cormorant 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 Big Cormorant Lake
These are the measurements Minnesota PCA publishes for Big Cormorant 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 24.8 ft down. Phosphorus 16.5 µg/L. Chlorophyll-a 2.2 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 24.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 16.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.2µg/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 Big Cormorant Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Targeted Survey on August 25, 2025 caught 14.42 walleye per gill net at Big Cormorant Lake. Length samples in the latest survey that recorded them ran 7–23 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Big Cormorant Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
21 surveys on file from MN DNR Fisheries. Most recent: 2025-08-25 (Targeted Survey).
21 surveys on file · most recent 2025-08-25 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluntnose Minnow | 22.48 | ||
| Rock Bass | 15.99 | 4–10 in 2025-08-25 | 0.44 lb |
| Largemouth Bass | 14.43 | 7–15 in 2025-08-25 | 0.95 lb |
| Walleye | 12.67 | 7–23 in 2025-08-25 | 1.64 lb |
| Bluegill | 9.43 | 3–9 in 2025-08-25 | 0.3 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.
Rock Bass
Largemouth Bass
Walleye
Bluegill
From the 2025-08-25 survey
Big Cormorant is a 3,657-acre lake located in southwestern Becker County. It is well-suited to Walleyes, which were reportedly introduced during the early part of the 20th century. A targeted fisheries survey using 12 gill nets was completed in August 2025 to assess the Walleye population of Big Cormorant Lake. Gill…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Big Cormorant Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Big CormorantFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Big Cormorant (1198)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Big CormorantFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Big CormorantPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
75 ft
Surface area
3,657 acres
Shoreline
18.7 mi
Littoral zone
22%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
35 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,352 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Cormorant Lake (West)Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Big Cormorant Lake
Compare lakeside cabins, hotels, and vacation rentals near Big Cormorant Lake in Becker 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 Big Cormorant 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 Big Cormorant Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Big Cormorant Lake
- → Big Cormorant Lake fishing: DNR survey catch rates, species & stocking
- → Big Cormorant Lake fishing forecast & best times (species outlook + 14-day solunar calendar)
- → Big Cormorant Lake fishing regulations (limits, seasons, special rules)
- → Is it safe to eat fish from Big Cormorant Lake? (mercury & PFAS guide)
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: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Worsening+1.01 µg/L/yr6 years
Chlorophyll-a
Worsening+0.17 µg/L/yr6 years
Ice season
Typical ice-out
Apr 19
Earliest Apr 2, 2010 · Latest May 15, 2013
Typical ice-in
Nov 29
Earliest Nov 11, 1990 · Latest Dec 19, 2001
Most recent ice-out
May 10
2023
76 observations · Minnesota PCA ice records
EPA Impairment Status
Big Cormorant 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 MN03-0576-00 · Official waterbody report
Nearby Lakes in Becker County
Frequently asked questions about Big Cormorant Lake
Where is Big Cormorant Lake?
- Big Cormorant Lake is a lake in Becker County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Big Cormorant Lake?
- Big Cormorant Lake in Becker County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 24.8 ft visibility. Phosphorus: 16.5 µg/L. Chlorophyll-a (algae): 2.2 µg/L. Maximum depth: 75 ft. Surface area: 3657.12 acres.
Is Big Cormorant Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Big Cormorant Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is Big Cormorant Lake?
- Big Cormorant Lake has a maximum depth of 75 feet. The lake covers 3657.12 acres.
What fish are in Big Cormorant Lake?
- Fish species found in Big Cormorant Lake include black bullhead, black crappie, bluegill, brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Big Cormorant Lake is located in Becker County, Minnesota.
What did the DNR fisheries survey find at Big Cormorant Lake?
- Minnesota DNR's Targeted Survey on August 25, 2025 caught 14.42 walleye per gill net at Big Cormorant Lake. Length samples in the latest survey that recorded them ran 7–23 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Big Cormorant Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Big Cormorant Lake thaw?
- Big Cormorant Lake typically has ice-out around Apr 19. Ice typically forms around Nov 29. The open water season is approximately 224 days.
Are there boat ramps on Big Cormorant Lake?
- Big Cormorant Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Cormorant Lake (West). Public access is listed as yes.
Can I fish at Big Cormorant Lake?
- Big Cormorant 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 Big Cormorant 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 Becker County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Detroit Lakes Area area
Top lakes and where to stay in the Park Rapids Area area
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Red River of the North Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Big Cormorant Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Compare Big Cormorant Lake With Nearby Lakes
Where this data comes from
168 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
MNPCA168 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)
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