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LakeQuality

Briar Lake

NR
Not yet rated
6 ft clear · Eutrophic · 79 acres
Limited DataEutrophic

Briar Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6 ft visibility. Maximum depth: 21 ft. Surface area: 79.32 acres.

Clarity
6 ft
Typical in August
75°F
Max depth
21 ft
Area
79 acres
Trend
Stable
Public access
Yes
Ice-out
Apr 24

Next lake in St. Louis County

NRSpring Lake9.5 ft clear · St. Louis CountyView →
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Why Briar 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 Briar Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. 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.

Briar Lake is a 79-acre lake in St. Louis County, Minnesota with a maximum depth of 21 feet. The lake supports 3 documented fish species including black bullhead, rainbow trout, and white sucker. Public access is available.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-07. 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 Duluth

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Water quality measurements for Briar Lake

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

Murky, only visible to about 6 ft. Trophic State Index: 51.

MetricValueGrade
Water Clarity (Secchi Depth)6 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)51Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Briar Lake

Compare lakeside cabins, hotels, and vacation rentals near Briar Lake in St. Louis 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 Briar 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 →

Water Temperature

Briar Lake typically sits around 75°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 77°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
60°
Jun
69°
Jul
77°
Aug
75°
Sep
70°
Oct
Nov
Dec

Typical surface water temperature by month, from 17 field readings (20242025) via the EPA Water Quality Portal. See the full Briar Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth21 ft
Surface Area79 acres
Shoreline Length2.6 mi
Littoral Zone84%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Elevation
1,467 ft

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

Fish Species

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

Fishing Briar Lake

DNR Fisheries Survey Summary

3 surveys on file from MN DNR Fisheries. Most recent: 2009-10-12 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
White Sucker13.490.47 lb
Rainbow Trout5.270.47 lb
Black Bullhead4.330.35 lb
GOS2.250.11 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

64 fish · 515 in · 2009-10-12
2211056789101112131415

Rainbow Trout

39 fish · 713 in · 2009-10-12
179078910111213

Black Bullhead

50 fish · 49 in · 2009-10-12
26130456789

GOS

42 fish · 47 in · 2009-10-12
271404567

From the 2009-10-12 survey

Briar is a 89 acre lake with 67 acres (75%) of littoral area and a maximum depth of 21 feet. The lake is located 13 miles north of Duluth, Minnesota off Highway #44 on County Road #272. The lake has a carry-down access located along the southwest shore. A population assessment (trapnets only) was conducted during the…

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 Briar Lake. 4 reports on file.

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

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Stable+0.027 m/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (8 observations).

Typical Ice-Out
Apr 24
EarliestLatest
Ice-Out2021-04-09 (2021)2018-05-04 (2018)
Ice-In2018-11-10 (2018)2018-11-10 (2018)

Most recent ice-out: 2021-04-09

Nearby Lakes in St. Louis County

Frequently asked questions about Briar Lake

What is the water quality grade for Briar Lake?

Briar Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6 ft visibility. Maximum depth: 21 ft. Surface area: 79.32 acres.

Is Briar Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Briar Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

What is the water temperature of Briar Lake?

Briar Lake typically sits around 75°F at the surface in August, from 17 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Briar Lake?

Briar Lake has a maximum depth of 21 feet. The lake covers 79.32 acres.

What fish are in Briar Lake?

Fish species found in Briar Lake include black bullhead, rainbow trout, white sucker. Briar Lake is located in St. Louis County, Minnesota.

When does Briar Lake thaw?

Briar Lake typically has ice-out around Apr 24.

Where this data comes from

51 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA51 samples · 2020–2025

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

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Ice data from Minnesota DNR Climate