Trout Lake Deep
Cook County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Trout Lake Deep. Here is what has been measured.
- Mesotrophic
- Limited data
Trout Lake Deep in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.7 ft visibility. Phosphorus: 9.7 µg/L. Chlorophyll-a (algae): 4.3 µg/L.
Trout Lake Deep is a mesotrophic lake in Cook County, Minnesota. Overall water quality is improving over recent sampling years. Compared to the 43 other monitored lakes in Cook County, Trout Lake Deep ranks #31 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-09-20. Methodology: how these readings are compared.
What Trout Lake Deep is good for
From access and monitoring records, not editorial picks.
- Clear water10.7 ft of visibility
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 Trout 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 Trout Lake Deep
These are the measurements Minnesota PCA publishes for Trout Lake Deep, 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 10.7 ft. Phosphorus 9.7 µg/L. Chlorophyll-a 4.3 µg/L. TSI 42.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 9.7µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4.3µg/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. | 42 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Trout Lake Deep
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Trout Lake Deep typically sits around 63°F at the surface in September. Summer average is about 69°F. Usually warmest in Jul (about 71°F) and coldest in May (about 55°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (55°F) to its warmest (71°F).
Typical surface water temperature by month, from 197 field readings (2010–2024) via the EPA Water Quality Portal. See the full Trout Lake Deep water temperature breakdown →
Stays via Stay22
Stays near Trout Lake Deep
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Top-rated places to stay near Trout Lake Deep
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Fishing Trout Lake Deep
Water Quality Trend: Improving
Based on 5 years of monitoring (2020–2025).
Water clarity
Worsening4 years
Phosphorus
Improving-0.86 µg/L/yr4 years
Chlorophyll-a
Improving-0.1 µg/L/yr4 years
Nearby Lakes in Cook County
Frequently asked questions about Trout Lake Deep
Where is Trout Lake Deep?
- Trout 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 Trout Lake Deep?
- Trout Lake Deep in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.7 ft visibility. Phosphorus: 9.7 µg/L. Chlorophyll-a (algae): 4.3 µg/L.
Is Trout 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 Trout Lake Deep?
- Trout Lake Deep typically sits around 63°F at the surface in September, from 197 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
Explore Trout Lake Deep across LakeQuality
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Where this data comes from
161 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_WQX106 samples · 2022 - 21GPBCH - Grand Portage Beaches (Tribal)
21GPBCH55 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.