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LakeQuality

Crab Lake

NR
Not yet rated
420 acres
Limited Data

Crab Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Maximum depth: 57 ft. Surface area: 419.79 acres.

Max depth
57 ft
Area
420 acres
Public access
No

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ABurntside Lake16 ft clear · St. Louis CountyView →
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Why Crab 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 Crab Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).

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.

Crab Lake is a 420-acre lake in St. Louis County, Minnesota with a maximum depth of 57 feet. 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 2021-10-09. 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 Crab Lake

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

No clarity data.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples

Where to stay near Crab Lake

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

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Lake Details

CharacteristicValue
Maximum Depth57 ft
Surface Area420 acres
Shoreline Length10.5 mi
Littoral Zone52%
Public AccessNo

Lake Size & Watershed

Watershed (drainage) area
9 sq mi
Elevation
1,457 ft

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

Fishing Crab Lake

DNR Fisheries Survey Summary

4 surveys on file from MN DNR Fisheries. Most recent: 2025-07-28 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
White Sucker5.332.03 lb
Bluegill4.000.06 lb
Rock Bass3.110.18 lb
Smallmouth Bass3.031.31 lb
Northern Pike2.673.03 lb
Pumpkinseed2.330.14 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.

White Sucker

54 fish · 921 in · 2001-07-02
9509101112131415161718192021

Rock Bass

17 fish · 58 in · 2001-07-02
7405678

Smallmouth Bass

8 fish · 516 in · 2001-07-02
2105678910111213141516

Northern Pike

30 fish · 1633 in · 2001-07-02
530161820222426283032

From the 2025-07-28 survey

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Crab Lake on July 28th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake.…

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 Crab Lake. 1 report on file.

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

EPA Impairment Status

Crab Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Mercury

Source: EPA ATTAINS assessment unit MN69-0220-00 · Official waterbody report

Graded lakes near Crab Lake

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

Nearby Lakes in St. Louis County

Frequently asked questions about Crab Lake

What is the water quality grade for Crab Lake?

Crab Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Maximum depth: 57 ft. Surface area: 419.79 acres.

Is Crab Lake safe to swim in?

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

Crab Lake has a maximum depth of 57 feet. The lake covers 419.79 acres.

Where this data comes from

1 measurement from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA1 sample · 2021

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