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East Loon Lake

A
Grade A — Excellent
Excellent · #16 of 66 lakes in the county · 13.5 ft clear · Mesotrophic · 1,044 acres
Mesotrophic

East Loon Lake in Otter Tail County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13.5 ft visibility. Phosphorus: 13 µg/L. Chlorophyll-a (algae): 3.9 µg/L. Maximum depth: 105 ft. Surface area: 1044.33 acres.

Clarity
13.5 ft
Typical in August
74°F
Max depth
105 ft
Area
1,044 acres
Type
Mesotrophic
Trend
Declining
Public access
Yes
Ice-out
Apr 13

Next lake in Otter Tail County

ASybil Lake20 ft clear · Otter Tail CountyView →
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East Loon Lake is a 1,044-acre mesotrophic lake in Otter Tail County, Minnesota with a maximum depth of 105 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 17 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 65 other monitored lakes in Otter Tail County, East Loon Lake ranks #16 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Low algae

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.

Excellent for swimming, crystal clear water with minimal algae

Compare the safest swimming lakes near Detroit Lakes

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Water Quality Grade: A (Excellent)

Good clarity, visible to about 13.5 ft. Phosphorus level: 13 µg/L. Chlorophyll-a: 3.9 µg/L. Trophic State Index: 42.

MetricValueGrade
Water Clarity (Secchi Depth)13.5 ftNot graded
Phosphorus13 µg/LGood
Chlorophyll-a (Algae)3.9 µg/LGood
Trophic State Index (TSI)42Mesotrophic

Moderate nutrients, good water quality

Where to stay near East Loon Lake

Compare lakeside cabins, hotels, and vacation rentals near East Loon Lake in Otter Tail 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 East Loon Lake

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Planning a whole trip? See where to stay at Minnesota’s top lakes →

Water Temperature

East Loon Lake typically sits around 74°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 78°F) and coldest in Jun (about 69°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
Jun
69°
Jul
78°
Aug
74°
Sep
70°
Oct
Nov
Dec

Typical surface water temperature by month, from 19 field readings (20222022) via the EPA Water Quality Portal. See the full East Loon Lake water temperature breakdown →

Blue-Green Algae (Cyanobacteria)

No current satellite reading

There’s no recent EPA CyAN cyanobacteria estimate for East Loon Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (9,036 cells/mL) on May 9, 2026.

Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗

Lake Details

CharacteristicValue
Maximum Depth105 ft
Surface Area1,044 acres
Shoreline Length17.1 mi
Littoral Zone57%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
19 sq mi
Elevation
1,355 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Loon LakePublic

Fish Species

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

Fishing East Loon 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.

zebra mussel

DNR Fisheries Survey Summary

8 surveys on file from MN DNR Fisheries. Most recent: 2025-07-14 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluntnose Minnow37.42
Bluegill28.100.17 lb
Green Sunfish26.110.13 lb
Largemouth Bass13.091.01 lb
IOD9.49
BCS7.27

CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.

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

223 fish · 38 in · 2025-07-14
77390345678

Green Sunfish

2 fish · 33 in · 2008-07-28
2103

Largemouth Bass

24 fish · 516 in · 2025-07-14
9505678910111213141516

From the 2025-07-14 survey

Loon Lake is a 1,048-acre mesotrophic (moderately fertile) lake located in north-central Otter Tail County. The town of Vergas, MN abuts the northeast shoreline of the lake. The immediate watershed is composed primarily of agricultural land interspersed with hardwood woodlots. The lake has a maximum depth of 105 feet;…

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 East Loon Lake. 3 reports on file.

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

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.183 m/yr5
Phosphorus Declining+1.54 µg/L/yr5
Chlorophyll-a Declining+0.32 µg/L/yr5
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (4 observations).

Typical Ice-Out
Apr 13
EarliestLatest
Ice-Out2004-04-10 (2004)2022-05-07 (2022)
Ice-In2003-12-01 (2003)2003-12-01 (2003)

Most recent ice-out: 2022-05-07

EPA Impairment Status

East Loon Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Mercury

Source: EPA ATTAINS assessment unit MN56-0523-00 · Official waterbody report

County Ranking

Ranked #16 of 66 lakes in Otter Tail County

Nearby Lakes in Otter Tail County

Frequently asked questions about East Loon Lake

What is the water quality grade for East Loon Lake?

East Loon Lake in Otter Tail County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13.5 ft visibility. Phosphorus: 13 µg/L. Chlorophyll-a (algae): 3.9 µg/L. Maximum depth: 105 ft. Surface area: 1044.33 acres.

Is East Loon Lake safe to swim in?

Excellent for swimming, crystal clear water with minimal algae. East Loon Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.9 µg/L. Always check local health department advisories before swimming.

What is the water temperature of East Loon Lake?

East Loon Lake typically sits around 74°F at the surface in August, from 19 EPA Water Quality Portal field readings (2022–2022). That is a typical value for the month, not a live reading.

How deep is East Loon Lake?

East Loon Lake has a maximum depth of 105 feet. The lake covers 1044.33 acres.

What fish are in East Loon Lake?

Fish species found in East Loon Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. East Loon Lake is located in Otter Tail County, Minnesota.

When does East Loon Lake thaw?

East Loon Lake typically has ice-out around Apr 13.

Does East Loon Lake have blue-green algae?

There is no recent EPA CyAN cyanobacteria estimate for East Loon Lake (clouds, ice, or an off-season gap). The most recent reading was low (9,036 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.

Are there boat ramps on East Loon Lake?

East Loon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Loon Lake. Public access is listed as yes.

Mesotrophic Lakes in Minnesota

Where this data comes from

231 measurements from 3 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 WaterMNPCA231 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Two Reagent Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (3)

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

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Named boat-access points from the USGS National Boat Ramps inventory

Ice data from Minnesota DNR Climate