Long Trade Lake
Polk County, Wisconsin150 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Long Trade Lake. Here is what has been measured.
- Eutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- Curly-Leaf Pondweed
- 13 ft max depth
- Public access
Long Trade Lake in Polk County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 84.8 µg/L. Maximum depth: 13 ft. Surface area: 150 acres.
Wisconsin DNR lists Panfish as common on Long Trade Lake. DNR survey details →
Long Trade Lake is a 150-acre productive, nutrient-rich eutrophic lake in Polk County, Wisconsin with a maximum depth of 13 feet. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 54 other monitored lakes in Polk County, Long Trade Lake ranks #41 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-21. Methodology: how these readings are compared.
Long Trade Lake covers about 150 acres in Polk County. It has one public boat landing. If you are planning to stay, you can search lake houses and cabins around Long Trade Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Long Trade Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing3 species recorded
Swimming conditions
Readings onlyRecreation use not supported
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. Long Trade Lake is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Long Trade 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 Trade Lake
These are the measurements Wisconsin DNR publishes for Long Trade Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 3 ft of visibility. Phosphorus 84.8 µg/L. TSI 65.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 84.8µg/L | Poor 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. | 65 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Long Trade Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Long Trade Lake typically sits around 70°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 79°F) and coldest in Sep (about 70°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (70°F) to its warmest (79°F).
Typical surface water temperature by month, from 12 field readings (2024–2025) via the EPA Water Quality Portal. See the full Long Trade Lake water temperature breakdown →
Wisconsin DNR lists Panfish as common on Long Trade Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Trade Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. 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 1986. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
13 ft
Surface area
150 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
52 sq mi
HydroLAKES / HydroSHEDS
Shoreline
2.8 mi
HydroLAKES / HydroSHEDS
Elevation
961 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Atlas ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Long Trade Lake
Compare lakeside cabins, hotels, and vacation rentals near Long Trade Lake in Polk 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Long Trade Lake are listed below.
Top-rated places to stay near Long Trade Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Wisconsin’s top lakes →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Long Trade 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: Improving
Based on 7 years of monitoring (2020–2026).
Water clarity
Improving6 years
Phosphorus
Stable-1.62 µg/L/yr7 years
Reservoir Info (USACE NID)
Long Trade Lake is a man-made reservoir impounded by the Atlas Feed Mill (completed 1874), built primarily for recreation on the Trade River; gravity-type dam, 14 ft tall and 92 ft long.
- Surface area
- 153 ac
- Normal storage
- 1,100 ac-ft
- Max storage
- 1,610 ac-ft
- Drainage area
- 45 sq mi
- Hazard class
- Significant
- Owner
- Polk County
All listed purposes: Recreation;Recreation;Hydroelectric.
Source: USACE National Inventory of Dams, NID ID WI00173 · Operator website
EPA Impairment Status
Long Trade Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
Source: EPA ATTAINS assessment unit WI10005131 · Official waterbody report
Nearby Lakes in Polk County
Frequently asked questions about Long Trade Lake
Where is Long Trade Lake?
- Long Trade Lake is a lake in Polk 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 Trade Lake?
- Long Trade Lake in Polk County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 84.8 µg/L. Maximum depth: 13 ft. Surface area: 150 acres.
Is Long Trade Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Long Trade Lake is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Long Trade Lake?
- Long Trade Lake typically sits around 70°F at the surface in September, 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 Long Trade Lake?
- Long Trade Lake has a maximum depth of 13 feet. The lake covers 150 acres.
What fish are in Long Trade Lake?
- Fish species found in Long Trade Lake include Panfish, Largemouth Bass, Northern Pike. Long Trade Lake is located in Polk County, Wisconsin.
What did the DNR fisheries survey find at Long Trade Lake?
- Wisconsin DNR lists Panfish as common on Long Trade Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Trade Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Long Trade Lake?
- Long Trade Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Atlas Park. Public access is listed as yes.
Can I fish at Long Trade Lake?
- Long Trade Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. 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 Long Trade Lake across LakeQuality
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Where this data comes from
69 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_WQX69 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
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
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