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LakeQuality

Square Lake

NR
Not yet rated
5.5 ft clear · Eutrophic · 123 acres
Limited DataEutrophic

Square Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.5 ft visibility. Maximum depth: 7 ft. Surface area: 122.68 acres.

Clarity
5.5 ft
Max depth
7 ft
Area
123 acres
Public access
No

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NRKawishi Lake4.5 ft clear · Lake CountyView →
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Why Square 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 Square 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.

Square Lake is a 123-acre lake in Lake County, Minnesota with a maximum depth of 7 feet. The lake supports 7 documented fish species including green sunfish, northern pike, and rock bass. No public access — the lake is private or restricted.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-07-30. 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

Compare the safest swimming lakes near Ely

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Water quality measurements for Square Lake

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

Murky, only visible to about 5.5 ft. Trophic State Index: 53.

MetricValueGrade
Water Clarity (Secchi Depth)5.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)53Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Square Lake

Compare lakeside cabins, hotels, and vacation rentals near Square Lake in Lake 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 Square 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 Depth7 ft
Surface Area123 acres
Shoreline Length3.3 mi
Littoral Zone100%
Public AccessNo

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Elevation
1,640 ft

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

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Square Lake

DNR Fisheries Survey Summary

3 surveys on file from MN DNR Fisheries. Most recent: 2015-07-27 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
White Sucker13.461.92 lb
Yellow Perch11.740.18 lb
Walleye10.120.99 lb
Northern Pike3.860.95 lb
Smallmouth Bass1.331.57 lb
Rock Bass0.960.21 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

63 fish · 820 in · 2015-07-27
1790891011121314151617181920

Yellow Perch

33 fish · 59 in · 2015-07-27
126056789

Walleye

60 fish · 623 in · 2015-07-27
1680trophy 246810121416182022

Northern Pike

15 fish · 817 in · 2015-07-27
210891011121314151617

From the 2015-07-27 survey

Square Lake has an area of 122 acres, and a maximum depth of 7 feet. Square Lake is within the Boundary Waters Canoe Area Wilderness (BWCAW) approximately 2.5 miles by canoe from the Kawishiwi Lake access point via Kawishiwi Lake and the Kawishiwi River. Square Lake is part of the popular non-motorized canoe route…

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 Square Lake. 1 report on file.

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

EPA Impairment Status

Square 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 MN38-0074-00 · Official waterbody report

Nearby Lakes in Lake County

Frequently asked questions about Square Lake

What is the water quality grade for Square Lake?

Square Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.5 ft visibility. Maximum depth: 7 ft. Surface area: 122.68 acres.

Is Square Lake safe to swim in?

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

Square Lake has a maximum depth of 7 feet. The lake covers 122.68 acres.

What fish are in Square Lake?

Fish species found in Square Lake include green sunfish, northern pike, rock bass, smallmouth bass, walleye, white sucker, yellow perch. Square Lake is located in Lake County, Minnesota.

Eutrophic Lakes in Minnesota

Where this data comes from

1 measurement from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA1 sample · 2024

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