Otter Tail River Lake
Otter Tail River Lake in Otter Tail County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 55 ft. Surface area: 313.22 acres.
- Clarity
- 11.5 ft
- Typical in August
- 77°F
- Max depth
- 55 ft
- Area
- 313 acres
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Otter Tail County
Why Otter Tail River 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 Tail River 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 Tail River Lake is a 313-acre lake in Otter Tail County, Minnesota with a maximum depth of 55 feet. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including bluegill, hybrid sunfish, and pumpkinseed. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-15. 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 Tail River Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 11.5 ft. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Otter Tail River Lake
Compare lakeside cabins, hotels, and vacation rentals near Otter Tail River 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 River Lake
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Water Temperature
Otter Tail River Lake typically sits around 77°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 77°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 23 field readings (2011–2025) via the EPA Water Quality Portal. See the full Otter Tail River Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 55 ft |
| Surface Area | 313 acres |
| Shoreline Length | 9.1 mi |
| Littoral Zone | 44% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- West Red River LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Otter Tail River 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.
DNR Fisheries Survey Summary
6 surveys on file from MN DNR Fisheries. Most recent: 2021-05-25 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Largemouth Bass | 18.38 | 1.7 lb |
| Bluegill | 12.35 | 0.27 lb |
| Yellow Perch | 8.18 | 0.11 lb |
| Pumpkinseed | 5.63 | 0.16 lb |
| Northern Pike | 3.87 | 1.56 lb |
| Yellow Bass | 2.30 | 0.79 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.
Largemouth Bass
Bluegill
Yellow Perch
Pumpkinseed
From the 2021-05-25 survey
Red River Lake is a 305-acre impoundment of the Otter Tail River located in west-central Otter Tail County approximately seven miles north of Fergus Falls, MN. An active hydroelectric dam owned by Otter Tail Power Company is located along the west shoreline. The Otter Tail River flows into the lake along the east…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Otter Tail River Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Otter Tail River(Red RiveFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Otter Tail River(Red Rive (0946)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Otter Tail River(Red RiveFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Otter Tail River(Red RivePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.272 m/yr | 6 |
Graded lakes near Otter Tail River Lake
Otter Tail River Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Otter Tail County
Frequently asked questions about Otter Tail River Lake
What is the water quality grade for Otter Tail River Lake?
- Otter Tail River Lake in Otter Tail County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 55 ft. Surface area: 313.22 acres.
Is Otter Tail River Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Otter Tail River Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Otter Tail River Lake?
- Otter Tail River Lake typically sits around 77°F at the surface in August, from 23 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Otter Tail River Lake?
- Otter Tail River Lake has a maximum depth of 55 feet. The lake covers 313.22 acres.
What fish are in Otter Tail River Lake?
- Fish species found in Otter Tail River Lake include bluegill, hybrid sunfish, pumpkinseed. Otter Tail River Lake is located in Otter Tail County, Minnesota.
Are there boat ramps on Otter Tail River Lake?
- Otter Tail River Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include West Red River Lake. Public access is listed as yes.
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Where this data comes from
29 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA29 samples · 2020–2025
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory