Myrtle Lake
Vilas County, WisconsinMesotrophic
On the LakeGrade rubric, Myrtle Lake pulls an A: clarity at 10.2 ft and 17 µg/L of phosphorus put it in the top bracket for Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.
The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. A maximum depth of 29 ft puts Myrtle Lake in the middle of Wisconsin's depth distribution. At 28 acres, Myrtle Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Myrtle Lake ranks 73 of 191 in Vilas County — solidly in the upper half of the local distribution.
No invasive species are currently listed at Myrtle Lake — the lake remains off the Wisconsin infested-waters roster. The fishery is bass-led, with 3 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 2021-08-30. 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 10.2 ft. Phosphorus level: 17.2 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.2 ft | B |
| Phosphorus | 17.2 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 29 ft |
| Surface Area | 28 acres |
Fish Species
Click a species to see every graded lake where it is documented.
→ Best fishing times for Myrtle Lake (14-day solunar calendar)
→ Is it safe to eat fish from Myrtle Lake? (mercury & PFAS guide)
→ Myrtle Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: ↓ Declining
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.196 m/yr | 7 |
| Phosphorus | → Stable | -0.3 µg/L/yr | 6 |
Location
County Ranking
Ranked #73 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. 1 station on file (most recent sample 2021).
Fish Species (DNR-rated)
Reservoir Info (USACE NID)
Myrtle Lake is a man-made reservoir impounded by the Little Tamarack Flowage on the Little Tamarack Creek; earth-type dam, 10 ft tall.
- Surface area
- 200 ac
- Normal storage
- 2,000 ac-ft
- Max storage
- 2,490 ac-ft
- Drainage area
- 25 sq mi
- Hazard class
- Low
- Owner
- Little Tamarack Flowage, Baker Spring Lake District
Source: USACE National Inventory of Dams, NID ID WI20051 · Operator website · Matched by proximity (0.63 km)
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: 2021-08-30
Monitoring stations: 1
Where to stay near Myrtle Lake
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