Smith Lake
Flathead County, Montana17 acresView mapDirections
Montana DEQ publishes the water-quality measurements for Smith Lake. Here is what has been measured.
- Oligotrophic
- Limited data
Smith Lake in Flathead County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Phosphorus: 7.4 µg/L. Chlorophyll-a (algae): 0.8 µg/L. Surface area: 17.3 acres.
Smith Lake is a 17-acre cold, clear oligotrophic lake in Flathead County, Montana. Overall water quality is declining over recent sampling years. Compared to the 43 other monitored lakes in Flathead County, Smith Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, Montana DEQ, last sampled 2023-08-08. Methodology: how these readings are compared.
Smith Lake covers about 17 acres in Flathead County. If you are planning to stay, you can search lake houses and cabins around Smith Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Smith Lake is safe to swim in today is a call for the Montana Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Smith Lake
These are the measurements Montana DEQ publishes for Smith 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. Phosphorus 7.4 µg/L. Chlorophyll-a 0.8 µg/L. TSI 31.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 7.4µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 0.8µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 31 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Smith Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
17 acres
No bathymetric survey has been published for Smith Lake, so its depth is not documented here.
Stays via Stay22
Stays near Smith Lake
Compare lakeside cabins, hotels, and vacation rentals near Smith 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 Smith Lake
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Fishing Smith Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2012–2023).
Phosphorus
Worsening+0.3 µg/L/yr6 years
Chlorophyll-a
Worsening+0.34 µg/L/yr5 years
Reservoir Info (USACE NID)
Smith Lake is a man-made reservoir impounded by the Smith Lake Dam (completed 1938), built primarily for fish and wildlife pond on the Smith Creek; earth-type dam, 12 ft tall and 150 ft long.
- Surface area
- 17.3 ac
- Normal storage
- 95 ac-ft
- Max storage
- 131 ac-ft
- Drainage area
- 2.6 sq mi
- Hazard class
- High
- Owner
- STATE OF MONTANA, D.N.R.C., T.L.M.D.
Source: USACE National Inventory of Dams, NID ID MT03845 · Operator website
Nearby Lakes in Flathead County
Frequently asked questions about Smith Lake
Where is Smith Lake?
- Smith Lake is a lake in Flathead County, Montana. Its water-quality measurements are published by Montana DEQ and shown on this page as reported.
What is the water quality of Smith Lake?
- Smith Lake in Flathead County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Phosphorus: 7.4 µg/L. Chlorophyll-a (algae): 0.8 µg/L. Surface area: 17.3 acres.
Is Smith Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Smith Lake across LakeQuality
Planning a trip around Glacier?
Smith Lake is about 31 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 lakes in Montana
Other Lakes in Montana
Oligotrophic Lakes in Montana
Where this data comes from
14 measurements from 1 monitoring station, 2012–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Montana Watershed
MTWTRSHD_WQX14 samples · 2012–2023
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 10200 H ~ Chlorophyll a-b-c Determination
- 4500 N C ~ Persufate Method for Total Nitrogen
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.