Lake of the Woods
Flathead County, MontanaView mapDirections
Montana DEQ publishes the water-quality measurements for Lake of the Woods. Here is what has been measured.
- 25 ft max depth
- Limited data
Ask about Lake of the Woods
Answers come straight from the public measurements and survey records on this page.
Lake of the Woods in Flathead County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Phosphorus: 5 µg/L. Chlorophyll-a (algae): 0.1 µg/L.
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Lake of the Woods is a lake in Flathead County, Montana with an estimated average depth of about 25 feet.
Source: EPA Water Quality Portal sampling records, Montana DEQ, last sampled 2012-08-29. Grade methodology: LakeQuality methodology.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Lake of the Woods 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 Lake of the Woods
These are the measurements Montana DEQ publishes for Lake of the Woods, 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 5 µg/L. Chlorophyll-a 0.1 µg/L. TSI 18.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 5 µg/L | Measured, not scored |
| Chlorophyll-a (Algae) | 0.1 µg/L | Measured, not scored |
| Trophic State Index (TSI) | 18 | Oligotrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~25 ft est. |
| Average Depth | ~17 ft est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Montana has not published bathymetry for Lake of the Woods.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Lake of the Woods
Nearby Lakes in Flathead County
Frequently asked questions about Lake of the Woods
Where is Lake of the Woods?
- Lake of the Woods 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 Lake of the Woods?
- Lake of the Woods in Flathead County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Phosphorus: 5 µg/L. Chlorophyll-a (algae): 0.1 µg/L.
Is Lake of the Woods safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Lake of the Woods?
- No published bathymetric survey covers Lake of the Woods, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 25 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Lake of the Woods across LakeQuality
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Lake of the Woods is about 39 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.
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Where this data comes from
2 measurements from 1 monitoring station, 2012. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Montana Watershed
MTWTRSHD_WQX2 samples · 2012
Analytical methods
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)