Mann Lake
Mann Lake in Harney County, Oregon is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 363 acres.
- Area
- 363 acres
- Public access
- Yes
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Why Mann Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Mann Lake, no water-quality sampling on record for this lake.
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by Oregon DEQ and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
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, last sampled recent years. Grade methodology: LakeQuality methodology.
Watch Mann Lake water quality
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Swimming Safety
Not ratedElevated nutrients
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Mann Lake
These readings exist but are not enough for an A–F grade — see why.
No clarity data. Trophic State Index: undefined.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) |
Where to stay 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
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 363 acres |
| Public Access | Yes |
No bathymetric survey has been published for Mann Lake, so its depth is not documented here.
Recreation & Access
- 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
Fishing Mann Lake
Nearby Lakes in Harney County
Frequently asked questions about Mann Lake
Where is Mann Lake?
- Mann Lake is a lake in Harney County, Oregon. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.
What is the water quality grade for Mann Lake?
- Mann Lake in Harney County, Oregon is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 363 acres.
Is Mann Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Mann Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
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.
Explore Mann Lake across LakeQuality
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Where this data comes from
Measurements for Mann Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Named boat-access points from the USGS National Boat Ramps inventory