Mora Lake
Mora Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.5 ft visibility. Maximum depth: 40 ft. Surface area: 210.32 acres.
- Clarity
- 8.5 ft
- Max depth
- 40 ft
- Area
- 210 acres
- Trend
- ↑ Improving
- Public access
- No
Next lake in Cook County
Why Mora Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Mora Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Mora Lake is a 210-acre lake in Cook County, Minnesota with a maximum depth of 40 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-07-23. Grade methodology: LakeGrade methodology.
Watch Mora Lake water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Mora Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 8.5 ft. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Mora Lake
Compare lakeside cabins, hotels, and vacation rentals near Mora 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.
Top-rated places to stay near Mora Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 40 ft |
| Surface Area | 210 acres |
| Shoreline Length | 9.9 mi |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fishing Mora Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1987-09-23 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| White Sucker | 7.00 | 1.15 lb |
| Northern Pike | 2.17 | 3.25 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
From the 1987-09-23 survey
NORTHERN PIKE ARE PRESENT IN FAIR NUMBERS. GROWTH RATES ARE SLIGHTLY BELOW THE STATE AVERAGE. THERE APPEARS TO BE SOME MISSING NORTHERN PIKE YEAR CLASSES, AND NO LARGER FISH WERE TAKEN. WHITE SUCKER ARE PRESENT IN ABOVE AVERAGE NUMBERS, WITH A LARGE RANGE OF SIZES. YELLOW PERCH ARE PRESENT, PROBABLY IN LOW NUMBERS. NO…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mora Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MoraFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +1.83 m/yr | 2 |
EPA Impairment Status
Mora Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN16-0723-00 · Official waterbody report · Matched by proximity (2.17 km)
Nearby Lakes in Cook County
Frequently asked questions about Mora Lake
What is the water quality grade for Mora Lake?
- Mora Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.5 ft visibility. Maximum depth: 40 ft. Surface area: 210.32 acres.
Is Mora Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Mora Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Mora Lake?
- Mora Lake has a maximum depth of 40 feet. The lake covers 210.32 acres.
Explore Mora Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
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Where this data comes from
2 measurements from 1 monitoring station, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA2 samples · 2021–2022
Analytical methods
- Field measurement/observation, generic 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.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder