Morton Lake
Morton Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 10.5 ft visibility. Maximum depth: 29 ft. Surface area: 165 acres.
Wisconsin DNR lists Panfish as common on Morton Lake. DNR survey details →
- Clarity
- 10.5 ft
- Typical in August
- 70°F
- Max depth
- 29 ft
- Area
- 165 acres
- Trend
- ↑ Improving
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Why Morton Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Morton Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Morton Lake is a 165-acre lake in Vilas County, Wisconsin with a maximum depth of 29 feet. Overall water quality is improving over recent sampling years. The lake supports 5 documented fish species including Musky, Panfish, and Largemouth Bass.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-24. Grade methodology: LakeQuality methodology.
Watch Morton Lake water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Morton Lake
These readings exist but are not enough for an A–F grade — see why.
Good clarity, visible to about 10.5 ft. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Morton Lake
Compare lakeside cabins, hotels, and vacation rentals near Morton Lake in Vilas County, Wisconsin — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Morton Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Water Temperature
Morton Lake typically sits around 70°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 77°F) and coldest in Aug (about 70°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 12 field readings (2024–2025) via the EPA Water Quality Portal. See the full Morton Lake water temperature breakdown →
Wisconsin DNR lists Panfish as common on Morton Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Morton Lake — official chemistry is on file, not a letter, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1990. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 29 ft |
| Surface Area | 165 acres |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Morton Lake
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.75 m/yr | 5 |
| Phosphorus | ↑ Improving | -5.5 µg/L/yr | 2 |
EPA Impairment Status
Morton Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10007538 · Official waterbody report · Matched by proximity (2.03 km)
Graded lakes near Morton Lake
Morton Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Vilas County
Frequently asked questions about Morton Lake
Where is Morton Lake?
- Morton Lake is a lake in Vilas County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Morton Lake?
- Morton Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 10.5 ft visibility. Maximum depth: 29 ft. Surface area: 165 acres.
Is Morton Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Morton Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Morton Lake?
- Morton Lake typically sits around 70°F at the surface in August, from 12 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Morton Lake?
- Morton Lake has a maximum depth of 29 feet. The lake covers 165 acres.
What fish are in Morton Lake?
- Fish species found in Morton Lake include Musky, Panfish, Largemouth Bass, Northern Pike, Walleye. Morton Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Morton Lake?
- Wisconsin DNR lists Panfish as common on Morton Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Morton Lake — official chemistry is on file, not a letter, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Morton Lake across LakeQuality
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Where this data comes from
6 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX6 samples · 2024–2025
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes