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LakeQuality

Chub Lake

NR
Not yet rated
13.7 ft clear · Oligotrophic · 313 acres
Limited DataOligotrophic

Chub Lake in Carlton County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 13.7 ft visibility. Maximum depth: 28 ft. Surface area: 313.42 acres.

Clarity
13.7 ft
Typical in August
72°F
Max depth
28 ft
Area
313 acres
Trend
Stable
Public access
Yes
Ice-out
Apr 20
Open water
220 days

Next lake in Carlton County

CHay Lake6 ft clear · Carlton CountyView →
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Why Chub 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 Chub 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.

Chub Lake is a 313-acre lake in Carlton County, Minnesota with a maximum depth of 28 feet (15-foot average). The lake supports 11 documented fish species including black crappie, bluegill, and brown bullhead. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-08-25. 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

Get alerts for Chub Lake

Water quality measurements for Chub Lake

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

Good clarity, visible to about 13.7 ft. Trophic State Index: 39.

MetricValueGrade
Water Clarity (Secchi Depth)13.7 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)39Oligotrophic

Low nutrients, clear water, excellent for swimming

Where to stay near Chub Lake

Compare lakeside cabins, hotels, and vacation rentals near Chub Lake in Carlton 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 Chub 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

Chub Lake typically sits around 72°F at the surface in August. Summer average is about 70°F. Usually warmest in Jul (about 72°F) and coldest in May (about 55°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
55°
Jun
66°
Jul
72°
Aug
72°
Sep
Oct
Nov
Dec

Typical surface water temperature by month, from 10 field readings (20242025) via the EPA Water Quality Portal. See the full Chub Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth28 ft
Average Depth15 ft
Surface Area313 acres
Shoreline Length4.8 mi
Littoral Zone54%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
3 sq mi
Elevation
1,115 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Chub LakePublic

Fish Species

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

Fishing Chub Lake

Invasive & Introduced Species

Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.

Eurasian watermilfoil

DNR Fisheries Survey Summary

7 surveys on file from MN DNR Fisheries. Most recent: 2020-08-31 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Largemouth Bass38.621.08 lb
Bluegill7.430.12 lb
Northern Pike6.562.03 lb
Walleye5.303.15 lb
Black Crappie3.990.22 lb
Pumpkinseed2.950.14 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.

Largemouth Bass

12 fish · 914 in · 2020-08-31
42091011121314

Bluegill

97 fish · 28 in · 2020-08-31
422102345678

Northern Pike

101 fish · 1031 in · 2020-08-31
17901012141618202224262830

Walleye

4 fish · 1825 in · 2020-08-31
10trophy 241819202122232425

From the 2020-08-31 survey

Chub Lake is a 313-acre lake located near Carlton, Minnesota with 54% (169 acres) littoral area and a maximum depth of 28 feet. A county owned, concrete back-in access is located on the north end of the lake, near Chub Lake Park. Walleye and Largemouth Bass are the primary management species and Black Crappie is 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 Chub 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-0.033 m/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (23 observations).

Typical Ice-Out
Apr 20
Typical Ice-In
Nov 26

Estimated open water season: 220 days

EarliestLatest
Ice-Out2024-03-12 (2024)2014-05-09 (2014)
Ice-In2017-11-10 (2017)2015-12-27 (2015)

Most recent ice-out: 2024-03-12

EPA Impairment Status

Chub 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 MN09-0008-00 · Official waterbody report

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Chub Lake under Clean Water Act (NPDES) discharge permits.

  • Northern Natural Gas Co
    Carlton · 2.4 mi away · NPDES MN0050041

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

Graded lakes near Chub Lake

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

Nearby Lakes in Carlton County

Frequently asked questions about Chub Lake

What is the water quality grade for Chub Lake?

Chub Lake in Carlton County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 13.7 ft visibility. Maximum depth: 28 ft. Surface area: 313.42 acres.

Is Chub Lake safe to swim in?

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

Chub Lake typically sits around 72°F at the surface in August, from 10 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Chub Lake?

Chub Lake has a maximum depth of 28 feet and an average depth of 15 feet. The lake covers 313.42 acres.

What fish are in Chub Lake?

Fish species found in Chub Lake include black crappie, bluegill, brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow perch. Chub Lake is located in Carlton County, Minnesota.

When does Chub Lake thaw?

Chub Lake typically has ice-out around Apr 20. Ice typically forms around Nov 26. The open water season is approximately 220 days.

Are there boat ramps on Chub Lake?

Chub Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Chub Lake. Public access is listed as yes.

Where this data comes from

42 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 WaterMNPCA42 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

Impairment status from EPA ATTAINS 303(d) database

Regulated discharger data from EPA ECHO (ICIS-NPDES)

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Named boat-access points from the USGS National Boat Ramps inventory

Ice data from Minnesota DNR Climate