Where is Lake Hillsboro?

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

How deep is Lake Hillsboro?

Lake Hillsboro has a maximum depth of 24 feet and an average depth of 10.6 feet. The lake covers 106 acres.

Are there boat ramps on Lake Hillsboro?

Lake Hillsboro has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Hillsboro. Public access is listed as yes.

Can I fish at Lake Hillsboro?

Lake Hillsboro has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Illinois's fish and wildlife agency, so check its current regulations before you go.

Lake Hillsboro

Montgomery County, Illinois106 acresView map Directions

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

Max depth

24 ft

Bathymetric survey

Area

106 acres

Surface area

Shoreline

4.8 mi

Measured length

Impaired · Algal growth
24 ft max depth
Public access

See the measurements Directions Where to stay

Lake Hillsboro in Montgomery County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 24 ft. Surface area: 106 acres.

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Lake Hillsboro is a 106-acre lake in Montgomery County, Illinois with a maximum depth of 24 feet (11-foot average). Limited fish-species data available. Public access is available with 1 public boat landing.

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

What Lake Hillsboro is good for

From access and monitoring records, not editorial picks.

Boat launch1 documented ramp

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Lake Hillsboro is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.

Whether Lake Hillsboro 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 Lake Hillsboro

These are the measurements Illinois EPA publishes for Lake Hillsboro, 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 Lake Hillsboro

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

Lake Details

Max depth

24 ft

Average depth

10.6 ft

Surface area

106 acres

Shoreline

4.8 mi

Public access

Yes

Listed by Illinois EPA

Recreation & Access

Boat Landings

Yes

Public Access

Lake HillsboroPublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Stays via Stay22

Stays near Lake Hillsboro

Compare lakeside cabins, hotels, and vacation rentals near Lake Hillsboro in Montgomery 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 Lake Hillsboro

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Follow Lake Hillsboro’s readings

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Fishing Lake Hillsboro

→ Lake Hillsboro fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Lake Hillsboro is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Algal growthNoxious aquatic plantsNutrients (phosphorus, nitrogen)Turbidity

Designated uses not supporting: Other.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit IL_ROT · Official waterbody report

Nearby Lakes in Montgomery County

Glenn Shoals Lake1 ft clear · Hypereutrophic2.7 miView →Lake Glenn Shoals3.7 miView →Lou Yaeger Lake1.8 ft clear · Hypereutrophic7.4 miView →Coffeen Lake9 miView →Lake Lou Yaeger8.3 miView →Fivemile Lake10.8 miView →

Frequently asked questions about Lake Hillsboro

Where is Lake Hillsboro?: Lake Hillsboro is a lake in Montgomery County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Lake Hillsboro?: Lake Hillsboro in Montgomery County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 24 ft. Surface area: 106 acres.
Is Lake Hillsboro safe to swim in?: Nutrient and algae readings are not a swimming clearance. Lake Hillsboro is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
How deep is Lake Hillsboro?: Lake Hillsboro has a maximum depth of 24 feet and an average depth of 10.6 feet. The lake covers 106 acres.
Are there boat ramps on Lake Hillsboro?: Lake Hillsboro has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Hillsboro. Public access is listed as yes.
Can I fish at Lake Hillsboro?: Lake Hillsboro has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Illinois's fish and wildlife agency, so check its current regulations before you go.