Where is Longjohn Slough?

Longjohn Slough is a lake in Cook County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.

Longjohn Slough

Cook County, Illinois53 acresView map Directions

No nutrient or algae sampling on record from Illinois EPA for this lake.

Area

53 acres

Surface area

Shoreline

1.6 mi

Measured length

See the measurements Directions Where to stay

Longjohn Slough in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Surface area: 53 acres.

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Longjohn Slough is a 53-acre lake in Cook County, Illinois.

Source: EPA Water Quality Portal sampling records, Illinois EPA. Methodology: how these readings are compared.

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Longjohn Slough is safe to swim in today is a call for the Illinois Environmental Protection Agency and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Longjohn Slough

These are the measurements Illinois EPA publishes for Longjohn Slough, 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 Longjohn Slough

Answers come straight from the public measurements and survey records on this page.

Lake Details

Surface area

53 acres

Shoreline

1.6 mi

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

Stays via Stay22

Stays near Longjohn Slough

Compare lakeside cabins, hotels, and vacation rentals near Longjohn Slough in Cook County, Illinois — 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 Longjohn Slough

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Fishing Longjohn Slough

→ Longjohn Slough fishing regulations (limits, seasons, special rules)

Nearby Lakes in Cook County

Maple Lake0.6 miView →Bull Frog Lake1.2 miView →Bullfrog Lake1.4 ft clear · Hypereutrophic1.2 miView →Saganashkee Slough Lake0.8 ft clear · Hypereutrophic1.5 miView →Belly Deep Slough Lake1.5 miView →Horsetail Lake2.2 ft clear · Hypereutrophic3 miView →

Frequently asked questions about Longjohn Slough

Where is Longjohn Slough?: Longjohn Slough is a lake in Cook County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Longjohn Slough?: Longjohn Slough in Cook County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Surface area: 53 acres.
Is Longjohn Slough safe to swim in?: Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.