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LakeQuality

Armstrong Lake

NR
Not yet rated
117 acres

Armstrong Lake in Blue Earth County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 117 acres.

Area
117 acres

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Why Armstrong Lake has no grade

We grade a lake only when the monitoring record supports a letter: 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 Armstrong Lake, no water-quality sampling on record for this lake.

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.

Armstrong Lake is a 117-acre lake in Blue Earth County, Minnesota.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled recent years. Grade methodology: LakeQuality methodology.

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Swimming Safety

Not rated

Elevated nutrients

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Mankato

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Water quality measurements for Armstrong Lake

These readings exist but are not enough for an A–F grade — see why.

No clarity data. Trophic State Index: undefined.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)

Where to stay near Armstrong Lake

Compare lakeside cabins, hotels, and vacation rentals near Armstrong Lake in Blue Earth 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.

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Lake Details

CharacteristicValue
Surface Area117 acres

No bathymetric survey has been published for Armstrong Lake, so its depth is not documented here.

Fishing Armstrong Lake

Nearby Lakes in Blue Earth County

Frequently asked questions about Armstrong Lake

Where is Armstrong Lake?

Armstrong Lake is a lake in Blue Earth County, Minnesota. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.

What is the water quality grade for Armstrong Lake?

Armstrong Lake in Blue Earth County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 117 acres.

Is Armstrong Lake safe to swim in?

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

Where this data comes from

Measurements for Armstrong Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.

Other records on this page

Lake details from Minnesota DNR LakeFinder