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LakeQuality

Little Armstrong Lake

NR
Not yet rated
15.5 ft clear · Oligotrophic · 70 acres
Limited DataOligotrophic

Little Armstrong Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 15.5 ft visibility. Maximum depth: 26 ft. Surface area: 69.68 acres.

Clarity
15.5 ft
Max depth
26 ft
Area
70 acres
Trend
Stable
Public access
No

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BEagles Nest Lake15.5 ft clear · St. Louis CountyView →
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Why Little Armstrong 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 Little Armstrong 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.

Little Armstrong Lake is a 70-acre lake in St. Louis County, Minnesota with a maximum depth of 26 feet. The lake supports 2 documented fish species including largemouth bass and smallmouth bass. No public access — the lake is private or restricted.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-08-25. 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 Ely

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Water quality measurements for Little Armstrong Lake

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

Crystal clear, you can see 15.5 ft down. Trophic State Index: 38.

MetricValueGrade
Water Clarity (Secchi Depth)15.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)38Oligotrophic

Low nutrients, clear water, excellent for swimming

Where to stay near Little Armstrong Lake

Compare lakeside cabins, hotels, and vacation rentals near Little Armstrong 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 Little Armstrong 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 Depth26 ft
Surface Area70 acres
Shoreline Length2.2 mi
Littoral Zone66%
Public AccessNo

Lake Size & Watershed

Watershed (drainage) area
0 sq mi
Elevation
1,506 ft

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

Fish Species

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

Fishing Little Armstrong Lake

DNR Fisheries Survey Summary

2 surveys on file from MN DNR Fisheries. Most recent: 2018-07-09 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Largemouth Bass5.230.8 lb
Yellow Perch2.470.13 lb
Smallmouth Bass1.050.82 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.

Largemouth Bass

81 fish · 516 in · 2018-07-09
361805678910111213141516

Yellow Perch

29 fish · 110 in · 1998-07-06
95012345678910

Smallmouth Bass

9 fish · 916 in · 2018-07-09
210910111213141516

From the 2018-07-09 survey

Little Armstrong (Camp) Lake is located approximately 10 miles SW of Ely in the Superior National Forest. This small lake has good water clarity and aquatic vegetation can be commonly found in its waters. The surrounding landscape is covered with a canopy of mixed deciduous and coniferous tree species. Public access…

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 Little Armstrong Lake. 1 report 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-0.05 m/yr6
See year-by-year chart →

EPA Impairment Status

Little Armstrong 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 MN69-0218-00 · Official waterbody report · Matched by proximity (1.51 km)

Graded lakes near Little Armstrong Lake

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

Nearby Lakes in St. Louis County

Frequently asked questions about Little Armstrong Lake

What is the water quality grade for Little Armstrong Lake?

Little Armstrong Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 15.5 ft visibility. Maximum depth: 26 ft. Surface area: 69.68 acres.

Is Little Armstrong Lake safe to swim in?

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

Little Armstrong Lake has a maximum depth of 26 feet. The lake covers 69.68 acres.

What fish are in Little Armstrong Lake?

Fish species found in Little Armstrong Lake include largemouth bass, smallmouth bass. Little Armstrong Lake is located in St. Louis County, Minnesota.

Where this data comes from

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

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA2 samples · 2020

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