Marion Lake
Otter Tail County, Minnesota1,624 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Marion Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- zebra mussel
- 62 ft max depth
- Public access
Marion Lake in Otter Tail County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 11 ft visibility. Phosphorus: 18 µg/L. Chlorophyll-a (algae): 7.3 µg/L. Maximum depth: 62 ft. Surface area: 1623.77 acres.
Minnesota DNR's Standard Survey on June 23, 2025 caught 1.67 walleye per gill net at Marion Lake. DNR survey details →
Free interactive depth-contour map of Marion Lake, reaching a maximum surveyed depth of 60 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Marion Lake is a 1,624-acre mesotrophic lake in Otter Tail County, Minnesota with a maximum depth of 62 feet. Overall water quality is improving 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, Marion Lake ranks #51 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-02. Methodology: how these readings are compared.
Marion Lake covers about 1,600 acres in Otter Tail County. It has one public boat landing. The median ice-out date is April 16, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Marion Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Marion Lake is good for
From access and monitoring records, not editorial picks.
- Clear water11 ft of visibility
- Boat launch1 documented ramp
- Fishing17 species recorded
- Ice seasonIce-out around Apr 16
- Deep water62 ft surveyed max depth
- Big water1,624 acres
Swimming conditions
Readings onlyLow algae
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. Marion Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Marion 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 Marion Lake
These are the measurements Minnesota PCA publishes for Marion Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 11 ft. Phosphorus 18 µg/L. Chlorophyll-a 7.3 µg/L. TSI 46.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 11ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 18µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 7.3µg/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. | 46 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Marion Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Marion Lake typically sits around 67°F at the surface in September. Summer average is about 74°F. Usually warmest in Jul (about 76°F) and coldest in May (about 56°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (56°F) to its warmest (76°F).
Typical surface water temperature by month, from 101 field readings (2010–2025) via the EPA Water Quality Portal. See the full Marion Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Marion Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (111,686 cells/mL) on November 2, 2024.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on June 23, 2025 caught 1.67 walleye per gill net at Marion Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Marion Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2025-06-23 (Standard Survey).
12 surveys on file · most recent 2025-06-23 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluntnose Minnow | 133.78 | ||
| Bluegill | 47.08 | 3–8 in 2025-06-23 | 0.16 lb |
| Yellow Perch | 20.18 | 5–9 in 2025-06-23 | 0.15 lb |
| Yellow Bullhead | 15.86 | 7–13 in 2025-06-23 | 0.74 lb |
| Hybrid Sunfish | 9.19 | 3–8 in 2025-06-23 | 0.26 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
Yellow Perch
Yellow Bullhead
Hybrid Sunfish
From the 2025-06-23 survey
Marion Lake is a 1,664-acre mesotrophic (moderately fertile) lake located in north-central Otter Tail County approximately four miles southwest of Perham, MN. Marion Lake is included in the Otter Tail River Watershed. The immediate watershed is primarily composed of agricultural land interspersed with hardwood…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Marion Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MarionFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — MarionFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MarionPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
62 ft
Surface area
1,624 acres
Shoreline
9.1 mi
Littoral zone
42%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
17 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,329 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Marion LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Marion Lake
Compare lakeside cabins, hotels, and vacation rentals near Marion 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 Marion 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 Marion Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Marion 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 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Improving-0.9 µg/L/yr6 years
Chlorophyll-a
Stable-0.01 µg/L/yr6 years
Ice season
Typical ice-out
Apr 16
Earliest Mar 16, 2024 · Latest May 7, 2022
Typical ice-in
Nov 28
Earliest Nov 10, 1997 · Latest Dec 19, 2015
Most recent ice-out
Mar 16
2024
48 observations · Minnesota PCA ice records
EPA Impairment Status
Marion Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN56-0243-00 · Official waterbody report
Nearby Lakes in Otter Tail County
Frequently asked questions about Marion Lake
Where is Marion Lake?
- Marion Lake is a lake in Otter Tail County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Marion Lake?
- Marion Lake in Otter Tail County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 11 ft visibility. Phosphorus: 18 µg/L. Chlorophyll-a (algae): 7.3 µg/L. Maximum depth: 62 ft. Surface area: 1623.77 acres.
Is Marion Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Marion Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Marion Lake?
- Marion Lake typically sits around 67°F at the surface in September, from 101 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Marion Lake?
- Marion Lake has a maximum depth of 62 feet. The lake covers 1623.77 acres.
What fish are in Marion Lake?
- Fish species found in Marion 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. Marion Lake is located in Otter Tail County, Minnesota.
What did the DNR fisheries survey find at Marion Lake?
- Minnesota DNR's Standard Survey on June 23, 2025 caught 1.67 walleye per gill net at Marion Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Marion Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Marion Lake thaw?
- Marion Lake typically has ice-out around Apr 16. Ice typically forms around Nov 28. The open water season is approximately 226 days.
Does Marion Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Marion Lake (clouds, ice, or an off-season gap). The most recent reading was high (111,686 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Marion Lake?
- Marion Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Marion Lake. Public access is listed as yes.
Can I fish at Marion Lake?
- Marion 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 Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Marion Lake across LakeQuality
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Where this data comes from
382 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 Water
MNPCA382 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)
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)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate