Clark Lake
Clark Lake in Door County, Wisconsin has a water quality grade of B (Good). 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 →
- Clarity
- 12.5 ft
- Typical in August
- 77°F
- Max depth
- 25 ft
- Area
- 865 acres
- Type
- Oligotrophic
- Trend
- ↑ Improving
- Public access
- Yes
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Clark Lake is a 865-acre cold, clear oligotrophic lake in Door County, Wisconsin with a maximum depth of 25 feet. Water quality is graded B based on 1 sampling years through 2026. 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 3 public boat landings. 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. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyLow algae
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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Good clarity, visible to about 12.5 ft. Phosphorus level: 10.5 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | Not graded |
| Phosphorus | 10.5 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay 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
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
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.
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 a water-quality grade. LakeQuality grades Clark Lake B 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 1988. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 25 ft |
| Surface Area | 865 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Clark LakePublic
- Whitefish BayPublic
- Schauer ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded 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 data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.065 m/yr | 6 |
| Phosphorus | ↑ Improving | -0.33 µg/L/yr | 6 |
County Ranking
Ranked #2 of 5 lakes in Door County
Nearby Lakes in Door County
Frequently asked questions about Clark Lake
Where is Clark Lake?
- Clark Lake is a lake in Door County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Clark Lake?
- Clark Lake in Door County, Wisconsin has a water quality grade of B (Good). 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?
- Good for swimming, clear water with low algae levels. Clark Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
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 a water-quality grade. LakeQuality grades Clark Lake B 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.
Are there boat ramps on Clark Lake?
- Clark Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Clark Lake, Whitefish Bay, Schauer Park. Public access is listed as yes.
Explore Clark Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded 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 grade
Low nutrients, clear water, excellent for swimming
Wisconsin's cleanest and most-polluted lakes, ranked
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State Parks Near Clark Lake
Other Grade B 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)
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
Named boat-access points from the USGS National Boat Ramps inventory