Crystal Lake
Marquette County, Wisconsin119 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Crystal Lake. Here is what has been measured.
- Oligotrophic
- 60 ft max depth
- Public access
Crystal Lake in Marquette County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 16.8 ft visibility. Phosphorus: 11.5 µg/L. Maximum depth: 60 ft. Surface area: 119 acres.
Wisconsin DNR rates Panfish as abundant on Crystal Lake. DNR survey details →
Crystal Lake is a 119-acre cold, clear oligotrophic lake in Marquette County, Wisconsin with a maximum depth of 60 feet. Water clarity is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Trout. Public access is available. Compared to the 10 other monitored lakes in Marquette County, Crystal Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-05-26. Methodology: how these readings are compared.
What Crystal Lake is good for
From access and monitoring records, not editorial picks.
- Clear water16.8 ft of visibility
- Fishing3 species recorded
- Deep water60 ft surveyed max depth
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 Crystal 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 Crystal Lake
These are the measurements Wisconsin DNR publishes for Crystal Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 16.8 ft down. Phosphorus 11.5 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 16.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 11.5µg/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. | 38 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Crystal Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Crystal Lake typically sits around 63°F at the surface in October. Summer average is about 76°F. Usually warmest in Jul (about 78°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (61°F) to its warmest (78°F).
Typical surface water temperature by month, from 37 field readings (2024–2026) via the EPA Water Quality Portal. See the full Crystal Lake water temperature breakdown →
Wisconsin DNR rates Panfish as abundant on Crystal Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Crystal Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is stable. 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 2016. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
60 ft
Surface area
119 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.9 mi
HydroLAKES / HydroSHEDS
Elevation
830 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Crystal Lake
Compare lakeside cabins, hotels, and vacation rentals near Crystal Lake in Marquette 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 Crystal Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Crystal 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: Stable
Based on 7 years of monitoring (2020–2026).
Water clarity
Improving6 years
Phosphorus
Worsening+0.29 µg/L/yr7 years
Nearby Lakes in Marquette County
Frequently asked questions about Crystal Lake
Where is Crystal Lake?
- Crystal Lake is a lake in Marquette County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Crystal Lake?
- Crystal Lake in Marquette County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 16.8 ft visibility. Phosphorus: 11.5 µg/L. Maximum depth: 60 ft. Surface area: 119 acres.
Is Crystal 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 Crystal Lake?
- Crystal Lake typically sits around 63°F at the surface in October, from 37 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Crystal Lake?
- Crystal Lake has a maximum depth of 60 feet. The lake covers 119 acres.
What fish are in Crystal Lake?
- Fish species found in Crystal Lake include Panfish, Largemouth Bass, Trout. Crystal Lake is located in Marquette County, Wisconsin.
What did the DNR fisheries survey find at Crystal Lake?
- Wisconsin DNR rates Panfish as abundant on Crystal Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Crystal Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Crystal Lake?
- Public access to Crystal Lake is listed as yes on the lake record. 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 Crystal Lake across LakeQuality
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Where this data comes from
101 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_WQX101 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
- Total Phosphorus After Block Digestion
- 2130 B ~ Nephelometric Method
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