Lost Land Lake
Sawyer County, WisconsinMesotrophic
Lost Land Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.
A TSI near 45 places Lost Land Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 21 ft puts Lost Land Lake in the middle of Wisconsin's depth distribution. At 1,264 acres, Lost Land Lake is one of the larger lakes in Sawyer County, with partial shoreline records supporting multiple distinct use patterns. Among the 50 graded lakes in Sawyer County, Lost Land Lake sits at rank 20, above the county median.
Eurasian watermilfoil has been documented at Lost Land Lake, requiring shoreline management to keep dense mats from crowding native vegetation. Walleye are documented at Lost Land Lake, one of 6 fish species on record for the lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-07. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 10 ft. Phosphorus level: 17.2 µg/L. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10 ft | B |
| Phosphorus | 17.2 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 21 ft |
| Surface Area | 1.3K acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Lost Land Lake (14-day solunar calendar)
→ Is it safe to eat fish from Lost Land Lake? (mercury & PFAS guide)
→ Lost Land Lake fishing regulations (limits, seasons, special rules)
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.55 m/yr | 5 |
| Phosphorus | ↑ Improving | -1.58 µg/L/yr | 5 |
Location
County Ranking
Ranked #20 of 50 lakes in Sawyer County
Nearby Lakes in Sawyer County
More Wisconsin Lake Rankings
Other Grade A Lakes in Wisconsin
Washington County · Clarity: 11.8 ft
Washington County · Clarity: 12.6 ft
Walworth County · Clarity: 11 ft
Waukesha County · Clarity: 11.3 ft
Walworth County · Clarity: 20.2 ft
Kenosha County · Clarity: 10 ft
Mesotrophic Lakes in Wisconsin
Compare Lost Land Lake With Nearby Lakes
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1993. 6 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-09-07
Monitoring stations: 1