Lost Lake
Lost Lake in Sawyer County, Wisconsin has a water quality grade of A (Excellent). Water clarity: 10.6 ft visibility. Phosphorus: 19.5 µg/L. Chlorophyll-a (algae): 1.6 µg/L. Maximum depth: 13 ft. Surface area: 51 acres.
- Clarity
- 10.6 ft
- Max depth
- 13 ft
- Area
- 51 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
Next lake in Sawyer County
Lost Lake is a 51-acre mesotrophic lake in Sawyer County, Wisconsin with a maximum depth of 13 feet. Water quality is graded A based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years. The lake supports 2 documented fish species including Panfish and Largemouth Bass. Compared to the 44 other monitored lakes in Sawyer County, Lost Lake ranks #13 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-07-16. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 10.6 ft. Phosphorus level: 19.5 µg/L. Chlorophyll-a: 1.6 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.6 ft | Not graded |
| Phosphorus | 19.5 µg/L | Good |
| Chlorophyll-a (Algae) | 1.6 µg/L | Good |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Lost Lake
Compare lakeside cabins, hotels, and vacation rentals near Lost Lake in Sawyer County, Wisconsin — 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.
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 13 ft |
| Surface Area | 51 acres |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Lost Lake
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages.
Fish Species (DNR-rated)
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.15 m/yr | 5 |
| Phosphorus | ↓ Declining | +1 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +0.1 µg/L/yr | 5 |
County Ranking
Ranked #13 of 45 lakes in Sawyer County
Nearby Lakes in Sawyer County
Frequently asked questions about Lost Lake
What is the water quality grade for Lost Lake?
- Lost Lake in Sawyer County, Wisconsin has a water quality grade of A (Excellent). Water clarity: 10.6 ft visibility. Phosphorus: 19.5 µg/L. Chlorophyll-a (algae): 1.6 µg/L. Maximum depth: 13 ft. Surface area: 51 acres.
Is Lost Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Lost Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 1.6 µg/L. Always check local health department advisories before swimming.
How deep is Lost Lake?
- Lost Lake has a maximum depth of 13 feet. The lake covers 51 acres.
What fish are in Lost Lake?
- Fish species found in Lost Lake include Panfish, Largemouth Bass. Lost Lake is located in Sawyer County, Wisconsin.
Explore Lost Lake across LakeGrade
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Where this data comes from
32 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Lac Courte Oreilles (Tribal)
LCOWIS_WQX32 samples · 2021–2024
Analytical methods
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 4500 P F ~ Phosphorus in Water by Colorimetry Automated Ascorbic Acid Method
- 4500 P E ~ Phosphorus by Ascorbic Acid
- 10200 H ~ Chlorophyll a-b-c Determination
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.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes