Mann Lake is a lake in Harney County, Oregon. Its water-quality measurements are published by Oregon DEQ and shown on this page as reported.

Are there boat ramps on Mann Lake?

Mann Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Mann Lake (West), Mann Lake (East). Public access is listed as yes.

Can I fish at Mann Lake?

Mann Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Oregon's fish and wildlife agency, so check its current regulations before you go.

Are there campgrounds on Mann Lake?

Mann Lake has 1 public campground from USGS The National Map within 5 km, including Mann Lake Recreation Site. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.

Mann Lake

Harney County, Oregon363 acresView map Directions

No nutrient or algae sampling on record from Oregon DEQ for this lake.

Area

363 acres

Surface area

Shoreline

3.3 mi

Measured length

Impaired · Mercury
Public access

See the measurements Directions Where to stay

Mann Lake in Harney County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Surface area: 363 acres.

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Mann Lake is a 363-acre lake in Harney County, Oregon. Limited fish-species data available. Public access is available with 2 public boat landings.

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

What Mann Lake is good for

From access and monitoring records, not editorial picks.

Boat launch2 documented ramps
Camping1 public campground nearby

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Mann Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.

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

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Water quality measurements for Mann Lake

These are the measurements Oregon DEQ publishes for Mann 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 Mann Lake

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

Lake Details

Surface area

363 acres

Shoreline

3.3 mi

Public access

Yes

Listed by Oregon DEQ

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

Recreation & Access

Boat Landings

Yes

Public Access

Campgrounds

Mann Lake (West)Public
Mann Lake (East)Public

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

Public campgrounds near Mann Lake

Mann Lake Recreation Site0.4 km

Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes

Stays via Stay22

Stays near Mann Lake

Compare lakeside cabins, hotels, and vacation rentals near Mann Lake in Harney County, Oregon — 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 Mann Lake

Prices for Oct 16–18, 4 adults. Change dates on the map below.

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Fishing Mann Lake

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

EPA Impairment Status

Mann Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).

Causes of impairment

Mercury

Designated uses not supporting: Fish consumption.

Source: EPA ATTAINS assessment unit OR_LK_1712000907_09_101324 · Official waterbody report

Nearby Lakes in Harney County

Juniper Lake11.3 miView →Puhi-Pane Na-De Lake12.8 miView →Comegys Lake13.1 miView →Heath Lake15.6 miView →Ten Cent Lake17.3 miView →Frazier Lake Waterhole15.9 miView →

Frequently asked questions about Mann Lake

Where is Mann Lake?: Mann Lake is a lake in Harney County, Oregon. Its water-quality measurements are published by Oregon DEQ and shown on this page as reported.
What is the water quality of Mann Lake?: Mann Lake in Harney County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Surface area: 363 acres.
Is Mann Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Mann Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Are there boat ramps on Mann Lake?: Mann Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Mann Lake (West), Mann Lake (East). Public access is listed as yes.
Can I fish at Mann Lake?: Mann Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Oregon's fish and wildlife agency, so check its current regulations before you go.
Are there campgrounds on Mann Lake?: Mann Lake has 1 public campground from USGS The National Map within 5 km, including Mann Lake Recreation Site. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.