Moccasin Lake
Vilas County, WisconsinMesotrophic
Moccasin Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Vilas County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
A TSI near 42 places Moccasin Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 31 ft puts Moccasin Lake in the middle of Wisconsin's depth distribution. The lake is compact at 94 acres, with partial shoreline records and little volume to buffer nutrient inputs. Among the 191 graded lakes in Vilas County, Moccasin Lake sits at rank 79, above the county median.
No invasive species are currently listed at Moccasin Lake — the lake remains off the Wisconsin infested-waters roster. Walleye are documented at Moccasin Lake, one of 5 fish species on record for the lake. 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 2025-10-23. Grade methodology: LakeGrade methodology.
Watch Moccasin Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 11 ft. Phosphorus level: 13.9 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11 ft | B |
| Phosphorus | 13.9 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 31 ft |
| Surface Area | 94 acres |
Fish Species
Click a species to see every graded lake where it is documented.
→ Best fishing times for Moccasin Lake (14-day solunar calendar)
→ Is it safe to eat fish from Moccasin Lake? (mercury & PFAS guide)
→ Moccasin Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +3.051 m/yr | 3 |
| Phosphorus | ↑ Improving | -10.79 µg/L/yr | 3 |
Location
County Ranking
Ranked #79 of 191 lakes in Vilas County
Nearby Lakes in Vilas 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
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1997. 1 station 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
Fish and recreation data from Wisconsin DNR Lakes
Most recent sample: 2025-10-23
Monitoring stations: 2
Where to stay near Moccasin Lake
Compare lakeside cabins, hotels, and vacation rentals near Moccasin Lake in Vilas County, Wisconsin — live availability and prices for your trip.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.