Otter Lake
Otter Lake in Otter Tail County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 18 ft visibility. Maximum depth: 64 ft. Surface area: 77.13 acres.
- Clarity
- 18 ft
- Max depth
- 64 ft
- Area
- 77 acres
- Public access
- Yes
Next lake in Otter Tail County
Why Otter Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Otter Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Otter Lake is a 77-acre lake in Otter Tail County, Minnesota with a maximum depth of 64 feet (14-foot average). The lake supports 7 documented fish species including black crappie, bluegill, and largemouth bass. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-09-08. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Otter Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Crystal clear, you can see 18 ft down. Trophic State Index: 35.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 18 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 35 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Otter Lake
Compare lakeside cabins, hotels, and vacation rentals near Otter 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 Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 64 ft |
| Average Depth | 14 ft |
| Surface Area | 77 acres |
| Shoreline Length | 2.1 mi |
| Littoral Zone | 64% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- East Spirit LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Otter Lake
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 2007-06-11 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 46.04 | 0.15 lb |
| Pumpkinseed | 7.08 | 0.23 lb |
| Yellow Perch | 3.33 | 0.16 lb |
| Black Crappie | 2.61 | 0.38 lb |
| Northern Pike | 2.07 | 3.17 lb |
| Largemouth Bass | 1.20 | 0.32 lb |
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
Pumpkinseed
Yellow Perch
Black Crappie
From the 2007-06-11 survey
Otter Lake is 97-acre mesotrophic lake located in northwest Otter Tail County. Otter Lake is located within the Otter Tail River Watershed. There are no inlets or outlets connected to the lake. The immediate watershed is composed primarily of hardwood forest. The maximum depth of Otter Lake is 64 feet; however, 51% of…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Otter Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — OtterFisheries Lake Survey · MN DNR LakeFinder
EPA Impairment Status
Otter Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN56-0502-00 · Official waterbody report · Matched by proximity (2.63 km)
Graded lakes near Otter Lake
Otter Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Otter Tail County
Frequently asked questions about Otter Lake
What is the water quality grade for Otter Lake?
- Otter Lake in Otter Tail County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 18 ft visibility. Maximum depth: 64 ft. Surface area: 77.13 acres.
Is Otter Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Otter Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Otter Lake?
- Otter Lake has a maximum depth of 64 feet and an average depth of 14 feet. The lake covers 77.13 acres.
What fish are in Otter Lake?
- Fish species found in Otter Lake include black crappie, bluegill, largemouth bass, northern pike, pumpkinseed, white sucker, yellow perch. Otter Lake is located in Otter Tail County, Minnesota.
Are there boat ramps on Otter Lake?
- Otter Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include East Spirit Lake. Public access is listed as yes.
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Where this data comes from
4 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA4 samples · 2020
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
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