Mt Maud Lake
Cook County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Mt Maud Lake. Here is what has been measured.
- Eutrophic
- Limited data
Mt Maud Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.4 ft visibility. Phosphorus: 47 µg/L. Chlorophyll-a (algae): 16.8 µg/L.
Mt Maud Lake is a productive, nutrient-rich eutrophic lake in Cook County, Minnesota. Overall water quality is improving over recent sampling years. Compared to the 43 other monitored lakes in Cook County, Mt Maud Lake ranks #44 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. 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 Mt Maud 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 Mt Maud Lake
These are the measurements Minnesota PCA publishes for Mt Maud 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 3.4 ft. Phosphorus 47 µg/L. Chlorophyll-a 16.8 µg/L. TSI 59.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 47µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 16.8µg/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. | 59 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Mt Maud Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Mt Maud Lake typically sits around 55°F at the surface in October. Summer average is about 71°F. Usually warmest in Aug (about 73°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (54°F) to its warmest (73°F).
Typical surface water temperature by month, from 109 field readings (2011–2025) via the EPA Water Quality Portal. See the full Mt Maud Lake water temperature breakdown →
Stays via Stay22
Stays near Mt Maud Lake
Compare lakeside cabins, hotels, and vacation rentals near Mt Maud Lake 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Mt Maud Lake are listed below.
Top-rated places to stay near Mt Maud Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
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Fishing Mt Maud Lake
Water quality readings over time
3 seasons of samples on record (2021–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Worsening+6.5 µg/L/yr3 years
Chlorophyll-a
Improving-1.05 µg/L/yr2 years
Nearby Lakes in Cook County
Frequently asked questions about Mt Maud Lake
Where is Mt Maud Lake?
- Mt Maud Lake 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 Mt Maud Lake?
- Mt Maud Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.4 ft visibility. Phosphorus: 47 µg/L. Chlorophyll-a (algae): 16.8 µg/L.
Is Mt Maud Lake 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 Mt Maud Lake?
- Mt Maud Lake typically sits around 55°F at the surface in October, from 109 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
Explore Mt Maud Lake across LakeQuality
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Where this data comes from
64 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Grand Portage Reservation
GPC5_WQX64 samples · 2021–2025
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 5310 C ~ Total Organic Carbon in Water- Ultraviolet Oxidation Method
Monitoring station identifiers (1)
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.