Crystal Lake
Crystal Lake in Marquette County, Wisconsin has a water quality grade of B (Good). Water clarity: 16.8 ft visibility. Phosphorus: 11.5 µg/L. Maximum depth: 60 ft. Surface area: 119 acres.
- Clarity
- 16.8 ft
- Typical in August
- 76°F
- Max depth
- 60 ft
- Area
- 119 acres
- Type
- Oligotrophic
- Trend
- → Stable
- Public access
- Yes
Next lake in Marquette County
Crystal Lake is a 119-acre cold, clear oligotrophic lake in Marquette County, Wisconsin with a maximum depth of 60 feet. Water quality is graded B based on 1 sampling years through 2026. 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. Grade methodology: LakeGrade 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)
Crystal clear, you can see 16.8 ft down. Phosphorus level: 11.5 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 16.8 ft | Not graded |
| Phosphorus | 11.5 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay 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.
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Water Temperature
Crystal Lake typically sits around 76°F at the surface in August. 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.
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 →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 60 ft |
| Surface Area | 119 acres |
| Public Access | Yes |
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 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.
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)
Water Quality Trend: → Stable
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.814 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.29 µg/L/yr | 7 |
County Ranking
Ranked #3 of 11 lakes in Marquette County
Nearby Lakes in Marquette County
Frequently asked questions about Crystal Lake
What is the water quality grade for Crystal Lake?
- Crystal Lake in Marquette County, Wisconsin has a water quality grade of B (Good). 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?
- Good for swimming, clear water with low algae levels. Crystal Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
What is the water temperature of Crystal Lake?
- Crystal Lake typically sits around 76°F at the surface in August, 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.
Explore Crystal Lake across LakeGrade
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Low nutrients, clear water, excellent for swimming
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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)
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