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LakeQuality

Owl Lake

NR
Not yet rated
13 ft clear · Mesotrophic · 77 acres
Limited DataMesotrophic

Owl Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 13 ft visibility. Maximum depth: 70 ft. Surface area: 76.82 acres.

Clarity
13 ft
Max depth
70 ft
Area
77 acres
Trend
Declining
Public access
No

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NRCrooked Lake5.5 ft clear · Cook CountyView →
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Why Owl 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 Owl 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.

Owl Lake is a 77-acre lake in Cook County, Minnesota with a maximum depth of 70 feet. Overall water quality is declining 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 2022-07-22. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

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Water quality measurements for Owl Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Good clarity, visible to about 13 ft. Trophic State Index: 40.

MetricValueGrade
Water Clarity (Secchi Depth)13 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)40Mesotrophic

Moderate nutrients, good water quality

Where to stay near Owl Lake

Compare lakeside cabins, hotels, and vacation rentals near Owl 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 Owl Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Lake Details

CharacteristicValue
Maximum Depth70 ft
Surface Area77 acres
Shoreline Length2.6 mi
Littoral Zone39%
Public AccessNo

Lake Size & Watershed

Watershed (drainage) area
0 sq mi
Elevation
1,670 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Fishing Owl Lake

DNR Fisheries Survey Summary

3 surveys on file from MN DNR Fisheries. Most recent: 2024-08-05 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
White Sucker12.841.27 lb
Yellow Perch4.380.09 lb
BUB1.001.8 lb
Lake Trout0.346.82 lb

CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.

Length Distributions

Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.

White Sucker

85 fish · 720 in · 1993-06-30
16807891011121314151617181920

Yellow Perch

30 fish · 57 in · 1993-06-30
27140567

Lake Trout

1 fish · 2525 in · 1993-06-30
1025

From the 2024-08-05 survey

Temperature and dissolved oxygen measurements were collected in the deepest basin in Owl Lake on August 5, 2024, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake. During the summer, Lake Trout…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Owl Lake. 1 report on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 2 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.76 m/yr2

EPA Impairment Status

Owl Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Mercury

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN16-0723-00 · Official waterbody report · Matched by proximity (1.55 km)

Graded lakes near Owl Lake

Owl Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Cook County

Frequently asked questions about Owl Lake

What is the water quality grade for Owl Lake?

Owl Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 13 ft visibility. Maximum depth: 70 ft. Surface area: 76.82 acres.

Is Owl Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Owl 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 Owl Lake?

Owl Lake has a maximum depth of 70 feet. The lake covers 76.82 acres.

Where this data comes from

1 measurement from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA1 sample · 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