Fish Lake
Flathead County, MontanaView mapDirections
Not Rated: one monitoring station are on record, but they measured water clarity only. LakeQuality’s A–F method grades total phosphorus, total nitrogen, chlorophyll-a, and turbidity; clarity is shown, not scored.
- Limited data
Fish Lake in Flathead County, Montana is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 16.6 ft visibility.
- Clarity
- 16.6 ft
- Trend
- ↓ Declining
Stays via Stay22
Stays near Fish Lake
Compare lakeside cabins, hotels, and vacation rentals near Fish Lake in Flathead 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 Fish Lake
Prices for Sep 11–13, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Montana’s top lakes →
Watch Fish Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Why Fish Lake has no grade
Fish Lake has monitoring on record from one station, but only water clarity was measured. LakeQuality’s A–F letter uses total phosphorus, total nitrogen, chlorophyll-a, and turbidity against EPA National Lakes Assessment condition classes. With none of those grading measurements on record, Fish Lake is Not Rated — not an F. Its 16.6-foot median from 4 readings collected 2020–2023 is still shown as clarity, but clarity alone cannot earn a letter.
Not Rated is EPA Integrated Reporting Category 3 — insufficient information. 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.
Fish Lake is a lake in Flathead County, Montana. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, Montana DEQ, last sampled 2023-07-24. Grade methodology: LakeQuality methodology.
What Fish Lake is good for
From access and monitoring records, not editorial picks.
- Clear water16.6 ft of visibility
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Check local advisories before you swim.
Water quality measurements for Fish Lake
These readings exist but are not enough for an A–F grade — see why.
Crystal clear, you can see 16.6 ft down. TSI 37.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 16.6 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 37 | Oligotrophic |
Low nutrients, clear water. The letter is not a swimming clearance.
Fishing Fish Lake
Water Quality Trend: ↓ Declining
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.953 m/yr | 4 |
Graded lakes near Fish Lake
Fish Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Flathead County
Frequently asked questions about Fish Lake
Where is Fish Lake?
- Fish Lake is a lake in Flathead County, Montana. LakeQuality has not rated this lake (UNRATED) — the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity.
What is the water quality grade for Fish Lake?
- Fish Lake in Flathead County, Montana is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 16.6 ft visibility.
Is Fish Lake safe to swim in?
- The letter is not a swimming clearance. Check local advisories before you swim.
Explore Fish Lake across LakeQuality
3 documented falls within 12.1 mi, nearest Bird Woman Falls
Species activity outlook by water temperature and season
Where to stay at Montana's top lakes, each with its grade
Montana's cleanest and most-polluted lakes, ranked
Planning a trip around Glacier?
Fish Lake is about 6 miles from Glacier National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Glacier →More Montana Lake Rankings
Other Lakes in Montana
Oligotrophic Lakes in Montana
Where this data comes from
4 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS4 samples · 2020–2023
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.