Where is Flagstaff Lake?

Flagstaff Lake is a lake in Somerset County, Maine. Its water-quality measurements are published by Maine DEP and shown on this page as reported.

How deep is Flagstaff Lake?

Flagstaff Lake has a maximum depth of 48 feet. The lake covers 17377 acres.

Are there boat ramps on Flagstaff Lake?

Flagstaff Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Dead River (Lower), Flagstaff Lake, Flagstaff Lake (East Flagstaff Road). Public access is listed as yes.

Can I fish at Flagstaff Lake?

Flagstaff Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Maine's fish and wildlife agency, so check its current regulations before you go.

Flagstaff Lake

Somerset County, Maine17,377 acresView map Directions

No nutrient or algae sampling on record from Maine DEP for this lake.

Max depth

48 ft

Bathymetric survey

Area

17,377 acres

Surface area

Shoreline

108.1 mi

Measured length

Impaired · Habitat alterations
48 ft max depth
Public access

See the measurements Directions Where to stay

Flagstaff Lake in Somerset County, Maine has water-quality measurements published by Maine DEP, shown here as reported. Maximum depth: 48 ft. Surface area: 17377 acres.

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Flagstaff Lake is a 17,377-acre lake in Somerset County, Maine with a maximum depth of 48 feet. Limited fish-species data available. Public access is available with 3 public boat landings.

Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.

What Flagstaff Lake is good for

From access and monitoring records, not editorial picks.

Boat launch3 documented ramps
Deep water48 ft surveyed max depth
Big water17,377 acres

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Flagstaff Lake is listed impaired under Clean Water Act §303(d) (IR 4C) for habitat alterations. Check local advisories before you swim.

Whether Flagstaff Lake is safe to swim in today is a call for the Maine Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Flagstaff Lake

These are the measurements Maine DEP publishes for Flagstaff 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 Flagstaff Lake

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

Lake Details

Max depth

48 ft

Surface area

17,377 acres

Shoreline

108.1 mi

Public access

Yes

Listed by Maine DEP

The depth above comes from a bathymetric survey of this lake, not from a regional estimate.

Recreation & Access

Boat Landings

Yes

Public Access

Dead River (Lower)Public
Flagstaff LakePublic
Flagstaff Lake (East Flagstaff Road)Public

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

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Stays near Flagstaff Lake

Compare lakeside cabins, hotels, and vacation rentals near Flagstaff Lake in Somerset County, Maine — 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 Flagstaff Lake

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Fishing Flagstaff Lake

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

EPA Impairment Status

Flagstaff Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4C).

Causes of impairment

Habitat alterations

Designated uses not supporting: Aquatic life.

Source: EPA ATTAINS assessment unit ME0103000203_38L · Official waterbody report

Nearby Lakes in Somerset County

Basin Pond4.4 miView →West Carry Pond4.2 miView →Spring Lake4.7 miView →Lower Shaw Pond7.1 miView →Shaw Pond—View →Middle Carry Pond6.6 miView →

Frequently asked questions about Flagstaff Lake

Where is Flagstaff Lake?: Flagstaff Lake is a lake in Somerset County, Maine. Its water-quality measurements are published by Maine DEP and shown on this page as reported.
What is the water quality of Flagstaff Lake?: Flagstaff Lake in Somerset County, Maine has water-quality measurements published by Maine DEP, shown here as reported. Maximum depth: 48 ft. Surface area: 17377 acres.
Is Flagstaff Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Flagstaff Lake is listed impaired under Clean Water Act §303(d) (IR 4C) for habitat alterations. Check local advisories before you swim.
How deep is Flagstaff Lake?: Flagstaff Lake has a maximum depth of 48 feet. The lake covers 17377 acres.
Are there boat ramps on Flagstaff Lake?: Flagstaff Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Dead River (Lower), Flagstaff Lake, Flagstaff Lake (East Flagstaff Road). Public access is listed as yes.
Can I fish at Flagstaff Lake?: Flagstaff Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Maine's fish and wildlife agency, so check its current regulations before you go.