Long Lake
Iron County, Wisconsin370 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Long Lake. Here is what has been measured.
- 34 ft max depth
- Limited data
Long Lake in Iron County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5.5 ft visibility. Maximum depth: 34 ft. Surface area: 370 acres.
Wisconsin DNR lists Musky as common on Long Lake. DNR survey details →
Long Lake is a 370-acre lake in Iron County, Wisconsin with a maximum depth of 34 feet. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-09-11. Methodology: how these readings are compared.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Fishing6 species recorded
- Deep water34 ft surveyed max depth
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Long 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 Long Lake
These are the measurements Wisconsin DNR publishes for Long Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5.5 ft. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| 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. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Musky as common on Long Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long 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 2004. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
34 ft
Surface area
370 acres
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Stays near Long Lake
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Follow Long Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Long 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
Stable7 years
Phosphorus
Stable+0.08 µg/L/yr6 years
Nearby Lakes in Iron County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Iron County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Iron County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5.5 ft visibility. Maximum depth: 34 ft. Surface area: 370 acres.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Long Lake?
- Long Lake has a maximum depth of 34 feet. The lake covers 370 acres.
What fish are in Long Lake?
- Fish species found in Long Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Long Lake is located in Iron County, Wisconsin.
What did the DNR fisheries survey find at Long Lake?
- Wisconsin DNR lists Musky as common on Long Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long 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.
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Where this data comes from
1 measurement from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX1 sample · 2022
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
Fish and recreation data from Wisconsin DNR Lakes