Clark Lake
Door County, Wisconsin865 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Clark Lake. Here is what has been measured.
- Oligotrophic
- 4 aquatic invasives
- 25 ft max depth
- Public access
Clark Lake in Door County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 12.5 ft visibility. Phosphorus: 10.5 µg/L. Maximum depth: 25 ft. Surface area: 865 acres.
Wisconsin DNR lists Panfish as common on Clark Lake. DNR survey details →
Clark Lake is a 865-acre cold, clear oligotrophic lake in Door County, Wisconsin with a maximum depth of 25 feet. Overall water quality is improving over recent sampling years. The lake supports 6 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Public access is available with 1 public boat landing. Compared to the 4 other monitored lakes in Door County, Clark Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-04-27. Methodology: how these readings are compared.
Clark Lake covers about 870 acres in Door County. It has one public boat landing. If you are planning to stay, you can search lake houses and cabins around Clark Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Clark Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12.5 ft of visibility
- Boat launch1 documented ramp
- Fishing6 species recorded
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Clark 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 Clark Lake
These are the measurements Wisconsin DNR publishes for Clark Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 12.5 ft. Phosphorus 10.5 µg/L. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10.5µg/L | Good GoodFairPoor |
| 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. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Clark Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Clark Lake typically sits around 77°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 77°F) and coldest in Jun (about 64°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (64°F) to its warmest (77°F).
Typical surface water temperature by month, from 11 field readings (2024–2025) via the EPA Water Quality Portal. See the full Clark Lake water temperature breakdown →
Wisconsin DNR lists Panfish as common on Clark Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Clark Lake’s water-quality measurements separately, 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 1988. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
25 ft
Surface area
865 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
18 sq mi
HydroLAKES / HydroSHEDS
Shoreline
5.7 mi
HydroLAKES / HydroSHEDS
Elevation
584 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Clark 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 Clark Lake
Compare lakeside cabins, hotels, and vacation rentals near Clark Lake in Door 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 Clark Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Follow Clark Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Clark Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Improving-0.33 µg/L/yr6 years
Nearby Lakes in Door County
Frequently asked questions about Clark Lake
Where is Clark Lake?
- Clark Lake is a lake in Door County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Clark Lake?
- Clark Lake in Door County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 12.5 ft visibility. Phosphorus: 10.5 µg/L. Maximum depth: 25 ft. Surface area: 865 acres.
Is Clark Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Clark Lake?
- Clark Lake typically sits around 77°F at the surface in August, from 11 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Clark Lake?
- Clark Lake has a maximum depth of 25 feet. The lake covers 865 acres.
What fish are in Clark Lake?
- Fish species found in Clark Lake include Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Trout, Walleye. Clark Lake is located in Door County, Wisconsin.
What did the DNR fisheries survey find at Clark Lake?
- Wisconsin DNR lists Panfish as common on Clark Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Clark Lake’s water-quality measurements separately, 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.
Are there boat ramps on Clark Lake?
- Clark Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Clark Lake. Public access is listed as yes.
Can I fish at Clark Lake?
- Clark 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 Clark Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Wisconsin
Fish species and best lakes in Door County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Door County area
Where to stay at Wisconsin's top lakes, each with its readings
Wisconsin's cleanest lakes, ranked on agency measurements
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State Parks Near Clark Lake
Other Lakes in Wisconsin
Oligotrophic Lakes in Wisconsin
Compare Clark Lake With Nearby Lakes
Where this data comes from
51 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX51 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
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