Lake · St. Louis County · MN
Is Crab Lake safe to swim?
Use caution
Cyanobacteria conditions are elevated; use caution.
Updated July 18, 2026 · EPA CyAN satellite
Recent rain
0.6 in
Water type
Lake
Last updated
Jul 18
Bacteria
E. coli, fecal
Tested
Not monitored
Blue-green algae
cyanobacteria
Tested
44,875
cells/mL
Advisory over
100,000
cells/mL
Sampled Jun 27 · EPA CyAN satellite
Before you get in
Conditions change fast. Blooms and bacteria move with wind, rain, and runoff, and monitoring lags real time, so always look before you get in.
Skip water that is scummy or discolored, and keep children and dogs out of visible algae.
SwimZone for iPhone · launching soon
Know before you get in at Crab Lake.
Get an alert the day a bacteria or algae advisory goes up.
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