Margaret Lake
Polk County, WisconsinOligotrophic
On the LakeGrade rubric, Margaret Lake pulls an A: clarity at 50.9 ft and 11 µg/L of phosphorus put it in the top bracket for Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.
Trophically, Margaret Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake is compact at 42 acres, with partial shoreline records and little volume to buffer nutrient inputs. Margaret Lake ranks 19 of 77 in Polk County, putting it in the upper tier of locally monitored lakes.
Margaret Lake has no invasive species recorded in Wisconsin state databases as of 2024, though prevention practices still apply at all access points. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-09-09. Grade methodology: LakeGrade methodology.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 50.9 ft down. Phosphorus level: 10.8 µg/L. Trophic State Index: 29.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 50.9 ft | A |
| Phosphorus | 10.8 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 29 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 42 acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Margaret Lake (14-day solunar calendar)
→ Is it safe to eat fish from Margaret Lake? (mercury & PFAS guide)
→ Margaret Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +4 m/yr | 2 |
| Phosphorus | ↑ Improving | -0.5 µg/L/yr | 2 |
Location
County Ranking
Ranked #19 of 77 lakes in Polk County
Nearby Lakes in Polk County
More Wisconsin Lake Rankings
State Parks Near Margaret Lake
Other Grade A Lakes in Wisconsin
Waukesha County · Clarity: 14.6 ft
Waukesha County · Clarity: 13.8 ft
Walworth County · Clarity: 19 ft
Washington County · Clarity: 12 ft
Kenosha County · Clarity: 10.1 ft
Washington County · Clarity: 12.5 ft
Oligotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2024).
Fish Species (DNR-rated)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Fish and recreation data from Wisconsin DNR Lakes
Most recent sample: 2024-09-09
Monitoring stations: 2