Mineral Lake
Mineral Lake in Ashland County, Wisconsin has a water quality grade of C (Fair). Water clarity: 4.1 ft visibility. Phosphorus: 28.2 µg/L. Maximum depth: 29 ft. Surface area: 227 acres.
- Clarity
- 4.1 ft
- Typical in August
- 71°F
- Max depth
- 29 ft
- Area
- 227 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
Next lake in Ashland County
Mineral Lake is a 227-acre productive, nutrient-rich eutrophic lake in Ashland County, Wisconsin with a maximum depth of 29 feet. Water quality is graded C based on 1 sampling years through 2026. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 4 public boat landings. Compared to the 2 other monitored lakes in Ashland County, Mineral Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-04-30. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 4.1 ft. Phosphorus level: 28.2 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.1 ft | Not graded |
| Phosphorus | 28.2 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Mineral Lake
Compare lakeside cabins, hotels, and vacation rentals near Mineral Lake in Ashland 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 Mineral Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Water Temperature
Mineral Lake typically sits around 71°F at the surface in August. Summer average is about 71°F. Usually warmest in Aug (about 71°F) and coldest in Apr (about 45°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 12 field readings (2024–2025) via the EPA Water Quality Portal. See the full Mineral Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 29 ft |
| Surface Area | 227 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Potter LakePublic
- Mineral LakePublic
- Lake ThreePublic
- English LakeSemi-private
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Mineral Lake
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.137 m/yr | 4 |
| Phosphorus | ↓ Declining | +1.55 µg/L/yr | 5 |
EPA Impairment Status
Mineral Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10008925 · Official waterbody report
County Ranking
Ranked #3 of 3 lakes in Ashland County
Nearby Lakes With Higher Grades
Mineral Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Ashland County
Frequently asked questions about Mineral Lake
What is the water quality grade for Mineral Lake?
- Mineral Lake in Ashland County, Wisconsin has a water quality grade of C (Fair). Water clarity: 4.1 ft visibility. Phosphorus: 28.2 µg/L. Maximum depth: 29 ft. Surface area: 227 acres.
Is Mineral Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Mineral Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
What is the water temperature of Mineral Lake?
- Mineral Lake typically sits around 71°F at the surface in August, from 12 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Mineral Lake?
- Mineral Lake has a maximum depth of 29 feet. The lake covers 227 acres.
What fish are in Mineral Lake?
- Fish species found in Mineral Lake include Musky, Panfish, Largemouth Bass, Walleye. Mineral Lake is located in Ashland County, Wisconsin.
Are there boat ramps on Mineral Lake?
- Mineral Lake has 4 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Potter Lake, Mineral Lake, Lake Three, English Lake. Public access is listed as yes.
Explore Mineral Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
2 documented falls within 10.9 mi, nearest Copper Falls
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Species activity outlook by water temperature and season
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
36 measurements from 1 monitoring station, 2021–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX36 samples · 2021–2026
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
Impairment status from EPA ATTAINS 303(d) database
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