Otter Tail Lake
Otter Tail County, Minnesota14,079 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Otter Tail Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- zebra mussel
- 120 ft max depth
- Public access
Otter Tail Lake in Otter Tail County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12.1 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 5.5 µg/L. Maximum depth: 120 ft. Surface area: 14078.61 acres.
Minnesota DNR's Targeted Survey on September 4, 2024 caught 10.70 walleye per gill net at Otter Tail Lake. Length samples in the latest survey that recorded them ran 6–24 inches. DNR survey details →
Free interactive depth-contour map of Otter Tail Lake, reaching a maximum surveyed depth of 120 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Otter Tail Lake is a 14,079-acre mesotrophic lake in Otter Tail County, Minnesota with a maximum depth of 120 feet. Water clarity 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 2 public boat landings. Compared to the 65 other monitored lakes in Otter Tail County, Otter Tail Lake ranks #36 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Methodology: how these readings are compared.
At about 14,000 acres, Otter Tail Lake is large enough that where you stay decides which shore you see most of. It has 2 public boat landings, so a lakefront rental is not the only way to get a boat on the water. The median ice-out date is April 16, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Otter Tail Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Otter Tail Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12.1 ft of visibility
- Boat launch2 documented ramps
- Fishing17 species recorded
- Ice seasonIce-out around Apr 16
- Deep water120 ft surveyed max depth
- Big water14,079 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. Otter Tail Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Otter Tail 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 Otter Tail Lake
These are the measurements Minnesota PCA publishes for Otter Tail 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 12.1 ft. Phosphorus 16 µg/L. Chlorophyll-a 5.5 µg/L. TSI 44.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 16µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 5.5µg/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. | 44 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Otter Tail Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Targeted Survey on September 4, 2024 caught 10.70 walleye per gill net at Otter Tail Lake. Length samples in the latest survey that recorded them ran 6–24 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Otter Tail Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
13 surveys on file from MN DNR Fisheries. Most recent: 2024-09-04 (Targeted Survey).
13 surveys on file · most recent 2024-09-04 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Yellow Perch | 56.54 | 5–10 in 2024-09-04 | 0.14 lb |
| Walleye | 12.51 | 6–24 in 2024-09-04 | 0.92 lb |
| Tullibee (Cisco) | 3.29 | 8–13 in 2024-09-04 | 0.47 lb |
| Northern Pike | 3.10 | 16–32 in 2024-09-04 | 3.04 lb |
| White Sucker | 2.75 | 6–18 in 2024-09-04 | 2 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.
Yellow Perch
Walleye
Tullibee (Cisco)
Northern Pike
From the 2024-09-04 survey
Otter Tail Lake is a 13,725-acre mesotrophic (moderately fertile) lake located in central Otter Tail County. The city of Ottertail, MN abuts the east shoreline of the lake. Otter Tail Lake is part of the Otter Tail River chain of lakes. Rush, Big Pine, and Little Pine Lakes are located upstream, while Deer, East Lost,…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Otter Tail Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Otter TailFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — Otter TailFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Otter TailPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
120 ft
Surface area
14,079 acres
Shoreline
23.7 mi
Littoral zone
46%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
1,058 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,309 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Riverside (West)Public
- Highway 72 BridgePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Otter Tail Lake
Compare lakeside cabins, hotels, and vacation rentals near Otter Tail 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 Otter Tail 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 →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Otter Tail 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: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Improving-3.91 µg/L/yr6 years
Chlorophyll-a
Stable-0.09 µg/L/yr6 years
Ice season
Typical ice-out
Apr 16
Earliest Mar 16, 2024 · Latest May 13, 2013
Typical ice-in
Nov 29
Earliest Nov 29, 2005 · Latest Jan 4, 2024
Most recent ice-out
Apr 17
2025
55 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
Otter Tail Lake is a man-made reservoir impounded by the Otter Tail Lake (completed 1936), built primarily for other on the Otter Tail River; gravity-type dam, 10 ft tall and 125 ft long.
- Surface area
- 14,745 ac
- Normal storage
- 506,000 ac-ft
- Max storage
- 557,200 ac-ft
- Drainage area
- 1,160 sq mi
- Hazard class
- Low
- Owner
- MNDNR-EWR
Source: USACE National Inventory of Dams, NID ID MN00209 · Operator website
EPA Impairment Status
Otter Tail 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 MN56-0242-00 · Official waterbody report
Nearby Lakes in Otter Tail County
Frequently asked questions about Otter Tail Lake
Where is Otter Tail Lake?
- Otter Tail 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 Otter Tail Lake?
- Otter Tail Lake in Otter Tail County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12.1 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 5.5 µg/L. Maximum depth: 120 ft. Surface area: 14078.61 acres.
Is Otter Tail Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Otter Tail Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is Otter Tail Lake?
- Otter Tail Lake has a maximum depth of 120 feet. The lake covers 14078.61 acres.
What fish are in Otter Tail Lake?
- Fish species found in Otter Tail Lake include black bullhead, black crappie, bluegill, brown bullhead, hybrid sunfish, lake sturgeon, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Otter Tail Lake is located in Otter Tail County, Minnesota.
What did the DNR fisheries survey find at Otter Tail Lake?
- Minnesota DNR's Targeted Survey on September 4, 2024 caught 10.70 walleye per gill net at Otter Tail Lake. Length samples in the latest survey that recorded them ran 6–24 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Otter Tail Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
When does Otter Tail Lake thaw?
- Otter Tail Lake typically has ice-out around Apr 16. Ice typically forms around Nov 29. The open water season is approximately 227 days.
Are there boat ramps on Otter Tail Lake?
- Otter Tail Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Riverside (West), Highway 72 Bridge. Public access is listed as yes.
Can I fish at Otter Tail Lake?
- Otter Tail Lake has 2 documented boat landings 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.
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Where this data comes from
155 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
MNPCA155 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