Mt Maud Lake
Mt Maud Lake in Cook County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.4 ft visibility. Phosphorus: 47 µg/L. Chlorophyll-a (algae): 16.8 µg/L.
- Clarity
- 3.4 ft
- Typical in August
- 73°F
- Type
- Eutrophic
- Trend
- ↑ Improving
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Mt Maud Lake →
Next lake in Cook County
Mt Maud Lake is a productive, nutrient-rich eutrophic lake in Cook County, Minnesota. Water quality is graded D based on 2 sampling years through 2025. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 3.4 ft. Phosphorus level: 47 µg/L. Chlorophyll-a: 16.8 µg/L. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.4 ft | Not graded |
| Phosphorus | 47 µg/L | Poor |
| Chlorophyll-a (Algae) | 16.8 µg/L | Poor |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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 grade measures nutrients and algae, not lodging — cabins and rentals around Mt Maud Lake are listed below.
Top-rated places to stay near Mt Maud Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Mt Maud Lake typically sits around 73°F at the surface in August. 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.
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 →
Fishing Mt Maud Lake
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.05 m/yr | 3 |
| Phosphorus | ↓ Declining | +6.5 µg/L/yr | 3 |
| Chlorophyll-a | ↑ Improving | -1.05 µg/L/yr | 2 |
County Ranking
Ranked #44 of 44 lakes in Cook County
Nearby Lakes in Cook County
Frequently asked questions about Mt Maud Lake
What is the water quality grade for Mt Maud Lake?
- Mt Maud Lake in Cook County, Minnesota has a water quality grade of D (Nutrient-rich). 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?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Mt Maud Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 16.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Mt Maud Lake?
- Mt Maud Lake typically sits around 73°F at the surface in August, 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 LakeGrade
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High nutrients, frequent algae, reduced clarity
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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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.