Teal Lake Deep
Cook County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Teal Lake Deep. Here is what has been measured.
- Mesotrophic
- 6 aquatic invasives
- Public access
- Limited data
Teal Lake Deep in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4.1 ft visibility. Phosphorus: 15.5 µg/L. Chlorophyll-a (algae): 5.7 µg/L.
Teal Lake Deep is a mesotrophic lake in Cook County, Minnesota. Phosphorus level is declining over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 43 other monitored lakes in Cook County, Teal Lake Deep ranks #32 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-09-20. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Teal Lake Deep 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 Teal Lake Deep
These are the measurements Minnesota PCA publishes for Teal Lake Deep, 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 4.1 ft. Phosphorus 15.5 µg/L. Chlorophyll-a 5.7 µg/L. TSI 49.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 15.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 5.7µg/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. | 49 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Teal Lake Deep
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Teal Lake Deep typically sits around 53°F at the surface in October. Summer average is about 71°F. Usually warmest in Jul (about 72°F) and coldest in Oct (about 53°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (53°F) to its warmest (72°F).
Typical surface water temperature by month, from 64 field readings (2010–2022) via the EPA Water Quality Portal. See the full Teal Lake Deep water temperature breakdown →
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Teal Lake Deep. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fish Stocking History — SuperiorFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — SuperiorPublic Water Access Sites · MN DNR LakeFinder
Stays via Stay22
Stays near Teal Lake Deep
Compare lakeside cabins, hotels, and vacation rentals near Teal Lake Deep 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 Teal Lake Deep
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Fishing Teal Lake Deep
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 readings over time
2 seasons of samples on record (2020–2022). Calling a direction takes at least 4 years of the same measurement.
Phosphorus
Worsening+1.8 µg/L/yr2 years
Chlorophyll-a
Improving-4.05 µg/L/yr2 years
Nearby Lakes in Cook County
Frequently asked questions about Teal Lake Deep
Where is Teal Lake Deep?
- Teal Lake Deep 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 Teal Lake Deep?
- Teal Lake Deep in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4.1 ft visibility. Phosphorus: 15.5 µg/L. Chlorophyll-a (algae): 5.7 µg/L.
Is Teal Lake Deep safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Teal Lake Deep?
- Teal Lake Deep typically sits around 53°F at the surface in October, from 64 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
Can I fish at Teal Lake Deep?
- Public access to Teal Lake Deep 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.
Explore Teal Lake Deep across LakeQuality
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
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State Parks Near Teal Lake Deep
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
38 measurements from 2 monitoring stations, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Grand Portage Reservation
GPC5_WQX24 samples · 2022 - 21GPBCH - Grand Portage Beaches (Tribal)
21GPBCH14 samples · 2020
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity by Nephelometry
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.