Middle Thompson Lake
Middle Thompson Lake in Lincoln County, Montana is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 575 acres.
- Area
- 575 acres
- Public access
- Yes
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Why Middle Thompson 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 Middle Thompson 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 Montana DEQ and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Middle Thompson Lake is a 575-acre lake in Lincoln County, Montana. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Montana DEQ, last sampled recent years. Grade methodology: LakeQuality methodology.
Watch Middle Thompson 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 Middle Thompson 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 Middle Thompson Lake
Compare lakeside cabins, hotels, and vacation rentals near Middle Thompson Lake in Lincoln County, Montana — 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 Middle Thompson Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 575 acres |
| Public Access | Yes |
No bathymetric survey has been published for Middle Thompson Lake, so its depth is not documented here.
Recreation & Access
- Thompson Chain of Lakes State ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Middle Thompson Lake
Nearby Lakes in Lincoln County
Frequently asked questions about Middle Thompson Lake
Where is Middle Thompson Lake?
- Middle Thompson Lake is a lake in Lincoln County, Montana. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.
What is the water quality grade for Middle Thompson Lake?
- Middle Thompson Lake in Lincoln County, Montana is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 575 acres.
Is Middle Thompson Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Middle Thompson 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 Middle Thompson Lake?
- Middle Thompson Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Thompson Chain of Lakes State Park. Public access is listed as yes.
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Where this data comes from
Measurements for Middle Thompson 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