Where is Unnamed Lake?

Unnamed Lake is a lake in Washington County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.

How deep is Unnamed Lake?

Unnamed Lake has a maximum depth of 60 feet. The lake covers 1799.22 acres.

When does Unnamed Lake thaw?

Unnamed Lake typically has ice-out around Apr 8. Ice typically forms around Dec 5. The open water season is approximately 241 days.

Can I fish at Unnamed Lake?

Public access to Unnamed Lake is listed as yes on the lake record. 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.

Unnamed Lake

Washington County, Minnesota1,799 acresView map Directions

Minnesota PCA publishes the water-quality measurements for Unnamed Lake. Here is what has been measured.

Clarity

3 ft

Murkier than most

Secchi · sampled 2025

Phosphorus

77 µg/L

More phosphorus than most

Measured by Minnesota PCA

Chlorophyll-a

28.5 µg/L

More algae than most

Measured by Minnesota PCA

Max depth

60 ft

Bathymetric survey

Area

1,799 acres

Surface area

Type

Eutrophic

Trophic class

Eutrophic
2 aquatic invasives
60 ft max depth
Public access

See the measurements Directions Where to stay

Unnamed Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 77 µg/L. Chlorophyll-a (algae): 28.5 µg/L. Maximum depth: 60 ft. Surface area: 1799.22 acres.

Minnesota DNR's Targeted Survey on July 29, 2024 caught 0.25 walleye per gill net at Unnamed Lake. DNR survey details →

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Unnamed Lake is a 1,799-acre productive, nutrient-rich eutrophic lake in Washington County, Minnesota with a maximum depth of 60 feet. The lake supports 12 documented fish species including black bullhead, black crappie, and bluegill. Public access is available. Compared to the 74 other monitored lakes in Washington County, Unnamed Lake ranks #48 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-24. Methodology: how these readings are compared.

What Unnamed Lake is good for

From access and monitoring records, not editorial picks.

Fishing12 species recorded
Ice seasonIce-out around Apr 8
Deep water60 ft surveyed max depth
Big water1,799 acres

Swimming conditions

Readings only

Algae risk

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 Unnamed 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.

Compare swimming lakes near St. Paul →

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Water quality measurements for Unnamed Lake

These are the measurements Minnesota PCA publishes for Unnamed 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 77 µg/L. Chlorophyll-a 28.5 µg/L. TSI 64.

Water quality readings
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	77µg/L	Poor GoodFairPoor
Chlorophyll-a (algae)	28.5µg/L	Poor GoodFairPoor
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.	64	Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic

High nutrients, frequent algae, reduced clarity

Ask about Unnamed Lake

Answers come straight from the public measurements and survey records on this page.

DNR fisheries survey

Minnesota DNR's Targeted Survey on July 29, 2024 caught 0.25 walleye per gill net at Unnamed Lake.

A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Unnamed Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.

DNR Fisheries Survey Summary

23 surveys on file from MN DNR Fisheries. Most recent: 2024-07-29 (Targeted Survey).

23 surveys on file · most recent 2024-07-29 (Targeted Survey)

Species	Catch rate (CPUE)	Size	Avg weight
Bluntnose Minnow	37.28
Bluegill	35.71	4–8 in 2024-07-29	0.15 lb
Golden Shiner	12.06	5 in 2024-07-29	0.07 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.

Length Distributions

Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.

Bluegill

83 fish · 4–8 in · 2024-07-29

Golden Shiner

1 fish · 5–5 in · 2024-07-29

From the 2024-07-29 survey

Big Marine Lake is a 1,799 acre, class 24 lake located in northern Washington County. Big Marine Lake is mesotrophic, moderately fertile, and is primarily managed for Walleye and Largemouth Bass. Bluegill and Black Crappie are secondary management species. From 1995 to 2017, Big Marine Lake was stocked with Walleye…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Unnamed Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

—
Fisheries Lake Survey — Big Marine
Fisheries Lake Survey · MN DNR LakeFinder
—
Fish Stocking History — Big Marine
Fish Stocking History · MN DNR LakeFinder
—
Public Water Access Sites — Big Marine
Public Water Access Sites · MN DNR LakeFinder

Lake Details

Max depth

60 ft

Surface area

1,799 acres

Shoreline

16.8 mi

Littoral zone

64%

Share shallower than 15 ft

Public access

Yes

Listed by Minnesota PCA

Stays via Stay22

Stays near Unnamed Lake

Compare lakeside cabins, hotels, and vacation rentals near Unnamed 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Unnamed Lake are listed below.

Top-rated places to stay near Unnamed 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 Unnamed Lake’s readings

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Fish Species

black bullhead black crappie bluegill brown bullhead green sunfish hybrid sunfish largemouth bass northern pike pumpkinseed walleye yellow bullhead yellow perch

Click a species to see every lake where it is documented.

Fishing Unnamed 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.

Eurasian watermilfoilzebra mussel

Ice season

Apr 8

Open water - 241 days

Typical ice-out

Apr 8

Earliest Mar 31, 2026 · Latest Apr 25, 2014

Typical ice-in

Dec 5

Earliest Nov 28, 2005 · Latest Dec 14, 2004

Most recent ice-out

Mar 31

2026

8 observations · Minnesota PCA ice records

Nearby Lakes in Washington County

Sunnybrook Lake4.5 ft clear · Eutrophic—View →Klawitter Pond1.9 ft clear · Eutrophic—View →Long Lake8 ft clear · Mesotrophic—View →Clear Lake—View →Wood Pile Lake10 ft clear · Mesotrophic—View →Jane Lake13 ft clear · Mesotrophic—View →

Frequently asked questions about Unnamed Lake

Where is Unnamed Lake?: Unnamed 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 Unnamed Lake?: Unnamed Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 77 µg/L. Chlorophyll-a (algae): 28.5 µg/L. Maximum depth: 60 ft. Surface area: 1799.22 acres.
Is Unnamed Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Unnamed Lake?: Unnamed Lake has a maximum depth of 60 feet. The lake covers 1799.22 acres.
What fish are in Unnamed Lake?: Fish species found in Unnamed Lake include black bullhead, black crappie, bluegill, brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, yellow bullhead, yellow perch. Unnamed Lake is located in Washington County, Minnesota.
What did the DNR fisheries survey find at Unnamed Lake?: Minnesota DNR's Targeted Survey on July 29, 2024 caught 0.25 walleye per gill net at Unnamed Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Unnamed Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
When does Unnamed Lake thaw?: Unnamed Lake typically has ice-out around Apr 8. Ice typically forms around Dec 5. The open water season is approximately 241 days.
Can I fish at Unnamed Lake?: Public access to Unnamed Lake is listed as yes on the lake record. 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 Unnamed Lake across LakeQuality

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Fish species and best lakes in Washington County

Lake Fishing Forecast

Species activity outlook by water temperature and season

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Every Minnesota lake with its Minnesota PCA measurements

Lake water quality by country

Official ratings and named-lake measurements

State Parks Near Unnamed Lake

Afton State Park

State Park · 13.9 mi

William O'Brien State Park

State Park · 13.9 mi

Fort Snelling State Park

State Park · 17.2 mi

Other Lakes in Minnesota

Silver Lake

Ramsey County · 7 ft

Beaver Lake

Ramsey County · 7.7 ft

Bald Eagle Lake

Ramsey County · 5.6 ft

Wakefield Lake

Ramsey County · 5.9 ft

Kohlman Lake

Ramsey County · 3.6 ft

Keller Lake

Ramsey County · 4.3 ft

Eutrophic Lakes in Minnesota

Silver Lake Beaver Lake Bald Eagle Lake Gem Lake

Compare Unnamed Lake With Nearby Lakes

Unnamed Lake vs White Bear Lake

Washington County · 14.4 ft

Where this data comes from

858 measurements from 19 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA857 samples · 2020–2025
Minnesota Department of Agriculture - Pesticide MonitoringMNDA_PESTICIDE1 sample · 2022

Analytical methods

Field measurement/observation, generic method
Phosphorus by Two Reagent Colorimetry
10200 H ~ Chlorophyll a-b-c Determination
Phosphorus by Colorimetry
Analysis of Chlorophyll in Periphyton and Plankton
Turbidity, Nephelometric Method
2120 B ~ Color in Water by Visual Comparison

Monitoring station identifiers (19)

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