Clear Lake
Sawyer County, WisconsinOligotrophic
Clear Lake earns an A — every scored parameter (clarity and phosphorus) rates among the best monitored waters in Sawyer County. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.
The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. A maximum depth of 32 ft puts Clear Lake in the middle of Wisconsin's depth distribution. At 77 acres, Clear Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Among the 50 graded lakes in Sawyer County, Clear Lake ranks 2 — in the top quartile locally.
Eurasian watermilfoil has been documented at Clear Lake, requiring shoreline management to keep dense mats from crowding native vegetation. The fishery includes walleye among the lake's 4 documented species — a notable draw for Wisconsin anglers. 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 2025-09-13. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 17 ft down. Phosphorus level: 11.2 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 17 ft | A |
| Phosphorus | 11.2 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 32 ft |
| Surface Area | 77 acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Clear Lake (14-day solunar calendar)
→ Is it safe to eat fish from Clear Lake? (mercury & PFAS guide)
→ Clear 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 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.747 m/yr | 6 |
| Phosphorus | → Stable | -0.08 µg/L/yr | 6 |
Location
County Ranking
Ranked #2 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
Oligotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1995. 3 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Clear Lake covering fish populations, stocking, water quality, and management. 1 report on file.
- 2024Clear Lake netting and shocking survey, 2024Netting Survey · WI DNR · 2024 (PDF)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-09-13
Monitoring stations: 1