Mars Lake
Oneida County, Wisconsin40 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Mars Lake. Here is what has been measured.
- 24 ft max depth
- Public access
- Limited data
Mars Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5 ft visibility. Maximum depth: 24 ft. Surface area: 40 acres.
Wisconsin DNR lists Panfish as common on Mars Lake. DNR survey details →
Mars Lake is a 40-acre lake in Oneida County, Wisconsin with a maximum depth of 24 feet. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-17. Methodology: how these readings are compared.
What Mars Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing4 species recorded
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Mars Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Mars Lake
These are the measurements Wisconsin DNR publishes for Mars Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5 ft. TSI 54.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 54 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Mars Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Panfish as common on Mars Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mars Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is declining. 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. 1 station on file (most recent sample 2024).
Fish Species (DNR-rated)
Lake Details
Max depth
24 ft
Surface area
40 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
0 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
1,588 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Mars LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Mars Lake
Compare lakeside cabins, hotels, and vacation rentals near Mars Lake in Oneida 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 Mars Lake
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Follow Mars Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Mars Lake
Water quality readings over time
2 seasons of samples on record (2024–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Worsening2 years
Nearby Lakes in Oneida County
Frequently asked questions about Mars Lake
Where is Mars Lake?
- Mars Lake is a lake in Oneida County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Mars Lake?
- Mars Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5 ft visibility. Maximum depth: 24 ft. Surface area: 40 acres.
Is Mars Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Mars Lake?
- Mars Lake has a maximum depth of 24 feet. The lake covers 40 acres.
What fish are in Mars Lake?
- Fish species found in Mars Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Mars Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Mars Lake?
- Wisconsin DNR lists Panfish as common on Mars Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mars Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Mars Lake?
- Mars Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Mars Lake. Public access is listed as yes.
Can I fish at Mars Lake?
- Mars Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.
Explore Mars Lake across LakeQuality
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Where this data comes from
11 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_WQX11 samples · 2024–2025
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory