Long Lake
Washington County, Minnesota53 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Mesotrophic
- Eurasian watermilfoil
- 25 ft max depth
- Limited data
Long Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 8 ft visibility. Phosphorus: 25 µg/L. Chlorophyll-a (algae): 5.6 µg/L. Maximum depth: 25 ft. Surface area: 53.12 acres.
Minnesota DNR's Standard Survey on June 17, 1992 caught 1.00 northern pike per gill net at Long Lake. DNR survey details →
Long Lake is a 53-acre mesotrophic lake in Washington County, Minnesota with a maximum depth of 25 feet. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 74 other monitored lakes in Washington County, Long Lake ranks #25 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-22. Methodology: how these readings are compared.
Long Lake covers about 53 acres in Washington County. The median ice-out date is April 12, which is when the open-water season begins. Vrbo is where to look for cabins and lake homes around Long Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Ice seasonIce-out around Apr 12
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Long Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR 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 Minnesota PCA 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.
Moderate clarity, visible to about 8 ft. Phosphorus 25 µg/L. Chlorophyll-a 5.6 µg/L. TSI 48.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 25µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 5.6µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 48 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on June 17, 1992 caught 1.00 northern pike per gill net at Long Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1992-06-17 (Standard Survey).
1 survey on file · most recent 1992-06-17 (Standard Survey)
34 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 155.75 | 0.08 lb | |
| Bluegill | 15.00 | 0.14 lb | |
| Pumpkinseed | 4.25 | 0.08 lb | |
| Hybrid Sunfish | 2.50 | 0.11 lb | |
| Black Crappie | 2.50 | 0.16 lb | |
| Brown Bullhead | 1.50 | 0.31 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
From the 1992-06-17 survey
BLB ABUNDANCE WAS HIGH. GILLNET AND TRAPNET CATCHES WERE 3 AND 56 TIMES ABOVE THE LOCAL MEDIAN LEVELS RESPECTIVELY. HSF, PMK, BLG, AND BLC WERE SAMPLED AT ABOVE LOCAL MEDIAN ABUNDANCE. BLG PSD WAS 25. BLG AND BLC WERE PROBABLY INTRODUCED SINCE THE 1977 NETTING. NOP, BRB, AND GSF WERE SAMPLED NEAR LOCAL MEDIAN LEVELS.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Long Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — LongFisheries Lake Survey · MN DNR LakeFinder
Lake Details
Max depth
25 ft
Surface area
53 acres
Shoreline
2.1 mi
Littoral zone
83%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Stays via Stay22
Stays near Long Lake
Compare lakeside cabins, hotels, and vacation rentals near Long Lake in Washington County, Minnesota — 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 Long Lake
Prices for Oct 9–11, 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 Minnesota’s top lakes →
Follow Long Lake’s readings
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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.
Ice season
Typical ice-out
Apr 12
Earliest Mar 28, 2007 · Latest Apr 21, 2008
Typical ice-in
Dec 1
Earliest Nov 25, 2007 · Latest Dec 1, 2020
Most recent ice-out
Apr 12
2022
8 observations · Minnesota PCA ice records
Nearby Lakes in Washington County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Washington County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 8 ft visibility. Phosphorus: 25 µg/L. Chlorophyll-a (algae): 5.6 µg/L. Maximum depth: 25 ft. Surface area: 53.12 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 25 feet. The lake covers 53.12 acres.
What did the DNR fisheries survey find at Long Lake?
- Minnesota DNR's Standard Survey on June 17, 1992 caught 1.00 northern pike per gill net at Long Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
When does Long Lake thaw?
- Long Lake typically has ice-out around Apr 12. Ice typically forms around Dec 1. The open water season is approximately 233 days.
Can I fish at Long Lake?
- Public access to Long Lake is listed as no on the lake record, so confirm before you make the trip. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Long Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Washington County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the St. Croix Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Long Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
117 measurements from 3 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA117 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
Monitoring station identifiers (3)
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
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate