Johnson Lake
St. Louis County, Minnesota1,665 acresView mapDirections
No nutrient or algae sampling on record from Minnesota PCA for this lake.
- Impaired · Mercury
- 88 ft max depth
Johnson Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Maximum depth: 88 ft. Surface area: 1665 acres.
Johnson Lake is a 1,665-acre lake in St. Louis County, Minnesota with a maximum depth of 88 feet.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder. Methodology: how these readings are compared.
What Johnson Lake is good for
From access and monitoring records, not editorial picks.
- Deep water88 ft surveyed max depth
- Big water1,665 acres
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Johnson Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Johnson Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Johnson Lake
These are the measurements Minnesota PCA publishes for Johnson Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. TSI undefined.
Ask about Johnson Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
88 ft
Surface area
1,665 acres
Shoreline
21.4 mi
The depth above comes from a bathymetric survey of this lake, not from a regional estimate.
Stays via Stay22
Stays near Johnson Lake
Compare lakeside cabins, hotels, and vacation rentals near Johnson 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 Johnson Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
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 →
Follow Johnson Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Johnson Lake
EPA Impairment Status
Johnson Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Fish consumption.
Source: EPA ATTAINS assessment unit MN69-0691-00 · Official waterbody report
Nearby Lakes in St. Louis County
Frequently asked questions about Johnson Lake
Where is Johnson Lake?
- Johnson Lake is a lake in St. Louis County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Johnson Lake?
- Johnson Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Maximum depth: 88 ft. Surface area: 1665 acres.
Is Johnson Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Johnson Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
How deep is Johnson Lake?
- Johnson Lake has a maximum depth of 88 feet. The lake covers 1665 acres.
Explore Johnson Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in St. Louis County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Lake Vermilion Area area
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Lakes in the Rainy Lake Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
Other Lakes in Minnesota
Where this data comes from
Measurements for Johnson Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake details from Minnesota DNR LakeFinder