Roach Lake
Vilas County, WisconsinLimited DataOligotrophic
On the LakeGrade rubric, Roach Lake pulls an A: clarity at 75.5 ft and phosphorus readings still being added 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.
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 48 ft puts Roach Lake in the middle of Wisconsin's depth distribution. Roach Lake is small — 48 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Roach Lake ranks 99 of 202 in Vilas County — solidly in the upper half of the local distribution.
Roach Lake has no invasive species recorded in Wisconsin state databases as of 2023, though prevention practices still apply at all access points. The fishery is bass-led, with 2 documented species across the lake's records. 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 2023-08-15. 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 75.5 ft down. Trophic State Index: 15.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 75.5 ft | A |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 15 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 48 ft |
| Surface Area | 48 acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Roach Lake (14-day solunar calendar)
→ Is it safe to eat fish from Roach Lake? (mercury & PFAS guide)
→ Roach 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 | +1.154 m/yr | 3 |
Location
County Ranking
Ranked #99 of 202 lakes in Vilas County
Nearby Lakes in Vilas County
More Wisconsin Lake Rankings
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 2023).
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: 2023-08-15
Monitoring stations: 1