First Black Lake
First Black Lake in Iron County, Wisconsin has a water quality grade of C (Fair). Water clarity: 2.5 ft visibility. Phosphorus: 27.5 µg/L. Maximum depth: 19 ft. Surface area: 23 acres.
- Clarity
- 2.5 ft
- Typical in August
- 69°F
- Max depth
- 19 ft
- Area
- 23 acres
- Type
- Eutrophic
- Trend
- → Stable
Next lake in Iron County
First Black Lake is a 23-acre productive, nutrient-rich eutrophic lake in Iron County, Wisconsin with a maximum depth of 19 feet. Water quality is graded C based on 1 sampling years through 2026. The lake supports 5 documented fish species including Musky, Panfish, and Largemouth Bass. Compared to the 15 other monitored lakes in Iron County, First Black Lake ranks #15 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-07-03. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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)
Very murky, less than 2.5 ft of visibility. Phosphorus level: 27.5 µg/L. Trophic State Index: 58.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.5 ft | Not graded |
| Phosphorus | 27.5 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near First Black Lake
Compare lakeside cabins, hotels, and vacation rentals near First Black Lake in Iron 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 First Black Lake
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Water Temperature
First Black Lake typically sits around 69°F at the surface in August. Summer average is about 70°F. Usually warmest in Jul (about 72°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 31 field readings (2024–2026) via the EPA Water Quality Portal. See the full First Black Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 19 ft |
| Surface Area | 23 acres |
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 First Black Lake
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 2005. 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 | → Stable | -0.075 m/yr | 7 |
| Phosphorus | → Stable | -0.01 µg/L/yr | 5 |
County Ranking
Ranked #15 of 16 lakes in Iron County
Nearby Lakes With Higher Grades
First Black Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Iron County
Frequently asked questions about First Black Lake
What is the water quality grade for First Black Lake?
- First Black Lake in Iron County, Wisconsin has a water quality grade of C (Fair). Water clarity: 2.5 ft visibility. Phosphorus: 27.5 µg/L. Maximum depth: 19 ft. Surface area: 23 acres.
Is First Black Lake safe to swim in?
- Generally safe for swimming, moderate water quality. First Black Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
What is the water temperature of First Black Lake?
- First Black Lake typically sits around 69°F at the surface in August, from 31 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is First Black Lake?
- First Black Lake has a maximum depth of 19 feet. The lake covers 23 acres.
What fish are in First Black Lake?
- Fish species found in First Black Lake include Musky, Panfish, Largemouth Bass, Northern Pike, Walleye. First Black Lake is located in Iron County, Wisconsin.
Explore First Black Lake across LakeGrade
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Where this data comes from
86 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_WQX86 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