Cochran Lake
Cochran Lake in Vilas County, Wisconsin has a water quality grade of C (Fair). Water clarity: 6 ft visibility. Phosphorus: 29.3 µg/L. Maximum depth: 12 ft. Surface area: 133 acres.
Wisconsin DNR rates Northern Pike as abundant on Cochran Lake. DNR survey details →
- Clarity
- 6 ft
- Max depth
- 12 ft
- Area
- 133 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
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Cochran Lake is a 133-acre productive, nutrient-rich eutrophic lake in Vilas County, Wisconsin with a maximum depth of 12 feet. Water quality is graded C based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Compared to the 102 other monitored lakes in Vilas County, Cochran Lake ranks #90 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-27. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyModerate
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 6 ft. Phosphorus level: 29.3 µg/L. Trophic State Index: 52.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6 ft | Not graded |
| Phosphorus | 29.3 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Cochran Lake
Compare lakeside cabins, hotels, and vacation rentals near Cochran 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 Cochran Lake
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Wisconsin DNR rates Northern Pike as abundant on Cochran Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Cochran Lake C from EPA Water Quality Portal chemistry, 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 2010. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 12 ft |
| Surface Area | 133 acres |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Cochran Lake
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.357 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.06 µg/L/yr | 6 |
County Ranking
Ranked #90 of 103 lakes in Vilas County
Nearby Lakes With Higher Grades
Cochran Lake holds Grade C. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Vilas County
Frequently asked questions about Cochran Lake
Where is Cochran Lake?
- Cochran Lake is a lake in Vilas County, Wisconsin. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Cochran Lake?
- Cochran Lake in Vilas County, Wisconsin has a water quality grade of C (Fair). Water clarity: 6 ft visibility. Phosphorus: 29.3 µg/L. Maximum depth: 12 ft. Surface area: 133 acres.
Is Cochran Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Cochran Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
How deep is Cochran Lake?
- Cochran Lake has a maximum depth of 12 feet. The lake covers 133 acres.
What fish are in Cochran Lake?
- Fish species found in Cochran Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Cochran Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Cochran Lake?
- Wisconsin DNR rates Northern Pike as abundant on Cochran Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Cochran Lake C from EPA Water Quality Portal chemistry, 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 Cochran Lake across LakeQuality
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
38 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX38 samples · 2020–2025
Analytical methods
- Phosphorus by Colorimetry
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes