Margaret Lake
Cass County, Minnesota251 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Margaret Lake. Here is what has been measured.
- Eutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- zebra mussel
- 26 ft max depth
- Limited data
Margaret Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5.5 ft visibility. Phosphorus: 38.5 µg/L. Chlorophyll-a (algae): 21.5 µg/L. Maximum depth: 26 ft. Surface area: 250.69 acres.
Minnesota DNR's Standard Survey on June 16, 2025 caught 1.17 walleye per gill net at Margaret Lake. DNR survey details →
Margaret Lake is a 251-acre productive, nutrient-rich eutrophic lake in Cass County, Minnesota with a maximum depth of 26 feet. Overall water quality is improving over recent sampling years. The lake supports 17 documented fish species including black crappie, bluegill, and bowfin (dogfish). No public access — the lake is private or restricted. Compared to the 103 other monitored lakes in Cass County, Margaret Lake ranks #102 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-27. Methodology: how these readings are compared.
What Margaret Lake is good for
From access and monitoring records, not editorial picks.
- Fishing17 species recorded
- Ice seasonIce-out around Apr 17
Swimming conditions
Readings onlyRecreation use not supported
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. Margaret Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Margaret 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 Margaret Lake
These are the measurements Minnesota PCA publishes for Margaret Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5.5 ft. Phosphorus 38.5 µg/L. Chlorophyll-a 21.5 µg/L. TSI 57.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 38.5µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 21.5µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 57 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Margaret Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Margaret Lake typically sits around 70°F at the surface in September. Summer average is about 76°F. Usually warmest in Jul (about 78°F) and coldest in Sep (about 70°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (70°F) to its warmest (78°F).
Typical surface water temperature by month, from 31 field readings (2022–2025) via the EPA Water Quality Portal. See the full Margaret Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Margaret Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (420,727 cells/mL) on November 1, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on June 16, 2025 caught 1.17 walleye per gill net at Margaret Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Margaret 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
11 surveys on file from MN DNR Fisheries. Most recent: 2025-06-16 (Standard Survey).
11 surveys on file · most recent 2025-06-16 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 20.91 | 2–8 in 2025-06-16 | 0.15 lb |
| Yellow Perch | 11.28 | 4–8 in 2025-06-16 | 0.1 lb |
| Green Sunfish | 6.80 | 3 in 2001-06-25 | 0.09 lb |
| Golden Shiner | 6.11 | 5 in 2025-06-16 | 0.07 lb |
| Yellow Bullhead | 4.45 | 8–14 in 2025-06-16 | 0.8 lb |
| Black Bullhead | 4.26 | 6–7 in 2013-06-24 | 0.54 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
Green Sunfish
Golden Shiner
From the 2025-06-16 survey
Margaret Lake is a 222-acre lake near the city of Nisswa in Cass County. It is part of the Gull Lake Chain of Lakes, with access possible through a navigable channel connection from Upper Gull. Northern Pike is the primary management species and a special regulation is used to achieve our management objective on the…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Margaret Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MargaretFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Margaret (1534)Aquatic Plant Report · MN DNR LakeFinder
Lake Details
Max depth
26 ft
Surface area
251 acres
Shoreline
5.5 mi
Littoral zone
26%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Stays via Stay22
Stays near Margaret Lake
Compare lakeside cabins, hotels, and vacation rentals near Margaret Lake in Cass 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Margaret Lake are listed below.
Top-rated places to stay near Margaret 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 →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Margaret 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
Ice season
Typical ice-out
Apr 17
Earliest Mar 17, 2004 · Latest May 10, 2013
Typical ice-in
Nov 18
Earliest Oct 24, 2002 · Latest Dec 5, 2001
Most recent ice-out
May 4
2022
25 observations · Minnesota PCA ice records
EPA Impairment Status
Margaret 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: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN11-0222-00 · Official waterbody report
Nearby Lakes in Cass County
Frequently asked questions about Margaret Lake
Where is Margaret Lake?
- Margaret Lake is a lake in Cass County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Margaret Lake?
- Margaret Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5.5 ft visibility. Phosphorus: 38.5 µg/L. Chlorophyll-a (algae): 21.5 µg/L. Maximum depth: 26 ft. Surface area: 250.69 acres.
Is Margaret Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Margaret Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Margaret Lake?
- Margaret Lake typically sits around 70°F at the surface in September, from 31 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.
How deep is Margaret Lake?
- Margaret Lake has a maximum depth of 26 feet. The lake covers 250.69 acres.
What fish are in Margaret Lake?
- Fish species found in Margaret Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, greater redhorse, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Margaret Lake is located in Cass County, Minnesota.
What did the DNR fisheries survey find at Margaret Lake?
- Minnesota DNR's Standard Survey on June 16, 2025 caught 1.17 walleye per gill net at Margaret Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Margaret 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 Margaret Lake thaw?
- Margaret Lake typically has ice-out around Apr 17. Ice typically forms around Nov 18. The open water season is approximately 215 days.
Does Margaret Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Margaret Lake (clouds, ice, or an off-season gap). The most recent reading was high (420,727 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Can I fish at Margaret Lake?
- Public access to Margaret Lake is listed as no on the lake record, so confirm before you make the trip. 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 Margaret Lake across LakeQuality
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Where this data comes from
322 measurements from 3 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
MNPCA322 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (3)
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 details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate