Leech Lake
Cass County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Leech Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- 2 aquatic invasives
- Public access
Leech Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12.5 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 2.7 µg/L.
Leech Lake is a mesotrophic lake in Cass County, Minnesota. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 103 other monitored lakes in Cass County, Leech Lake ranks #13 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-10. Methodology: how these readings are compared.
The median ice-out date is April 28, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Leech Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Leech Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12.5 ft of visibility
- Ice seasonIce-out around Apr 28
Leech Lake Water Quality Summary (2026)
A printable one-page summary for Leech Lake: clarity, phosphorus, algae, multi-year trend, depth, and fish — with sources.
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. Leech Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Leech 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 Leech Lake
These are the measurements Minnesota PCA publishes for Leech Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 12.5 ft. Phosphorus 12 µg/L. Chlorophyll-a 2.7 µg/L. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 12µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.7µg/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. | 40 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Leech Lake
Answers come straight from the public measurements and survey records on this page.
Current Conditions
USGS snapshot Jul 6, 2026, 4:30 AM from gauge 05205900 (Leech Lake at Sugar Point Near Federal Dam, MN). Station page ↗ — a live reading replaces this snapshot when the gauge responds. Missing live data is not an all-clear.
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Leech Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (40,179 cells/mL) on November 22, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Leech Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Public Water Access Sites — Leech (Main Basin)Public Water Access Sites · MN DNR LakeFinder
Stays via Stay22
Stays near Leech Lake
Compare lakeside cabins, hotels, and vacation rentals near Leech 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.
Top-rated places to stay near Leech 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 Leech Lake’s readings
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Fishing Leech 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
Phosphorus
Stable-0.09 µg/L/yr6 years
Chlorophyll-a
Improving-0.2 µg/L/yr6 years
Ice season
Typical ice-out
Apr 28
Earliest Apr 9, 1945 · Latest May 23, 1950
Typical ice-in
Nov 14
Earliest Nov 13, 2018 · Latest Nov 25, 2021
Most recent ice-out
May 8
2022
74 observations · Minnesota PCA ice records
EPA Impairment Status
Leech 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 MN11-0203-01 · Official waterbody report
Nearby Lakes in Cass County
Frequently asked questions about Leech Lake
Where is Leech Lake?
- Leech 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 Leech Lake?
- Leech Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12.5 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 2.7 µg/L.
Is Leech Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Leech Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
When does Leech Lake thaw?
- Leech Lake typically has ice-out around Apr 28. Ice typically forms around Nov 14. The open water season is approximately 200 days.
What is the water level at Leech Lake?
- The USGS snapshot on this page for Leech Lake is 94.71 ft of gage height, recorded Jul 6, 2026, 4:30 AM at gauge 05205900. Current Conditions hydrates a live NWIS reading from that same station when the gauge responds. A missed live fetch is not an all-clear.
Does Leech Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Leech Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (40,179 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Can I fish at Leech Lake?
- Public access to Leech Lake is listed as yes on the lake record. 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.
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Where this data comes from
588 measurements from 11 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
MNPCA566 samples · 2020–2025 - Leech Lake Band of Ojibwe
LEECHLAK_WQX22 samples · 2022–2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (11)
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
Ice data from Minnesota DNR Climate