Unnamed Lake
Unnamed Lake in Otter Tail County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 15.1 ft visibility. Phosphorus: 9 µg/L. Chlorophyll-a (algae): 2.6 µg/L. Maximum depth: 95 ft. Surface area: 1356.82 acres.
- Clarity
- 15.1 ft
- Max depth
- 95 ft
- Area
- 1,357 acres
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 25
- Open water
- 218 days
Next lake in Otter Tail County
Why Unnamed 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 Unnamed Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, 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.
Unnamed Lake is a 1,357-acre lake in Otter Tail County, Minnesota with a maximum depth of 95 feet. 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.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-08-02. 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 Unnamed Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Crystal clear, you can see 15.1 ft down. Phosphorus level: 9 µg/L. Chlorophyll-a: 2.6 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15.1 ft | Not graded |
| Phosphorus | 9 µg/L | Not graded |
| Chlorophyll-a (Algae) | 2.6 µg/L | Not graded |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Unnamed Lake
Compare lakeside cabins, hotels, and vacation rentals near Unnamed 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 Unnamed Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 95 ft |
| Surface Area | 1,357 acres |
| Shoreline Length | 8.1 mi |
| Littoral Zone | 42% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Unnamed 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
11 surveys on file from MN DNR Fisheries. Most recent: 2022-08-08 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 21.77 | 0.12 lb |
| BKF | 19.94 | — |
| Largemouth Bass | 18.06 | 1.52 lb |
| BCS | 15.36 | — |
| Yellow Perch | 12.09 | 0.14 lb |
| Bluntnose Minnow | 6.71 | — |
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
Largemouth Bass
Yellow Perch
From the 2022-08-08 survey
Stalker Lake is a 1,280-acre mesotrophic (moderately fertile) lake located in southwestern Otter Tail County, approximately seven miles southeast of Underwood, MN. Stalker Lake is part of the Pomme de Terre River Watershed. The Pomme de Terre River outlet is located along the southwest shoreline of the lake. The…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Unnamed Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — StalkerFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Stalker (1169)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — StalkerFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — StalkerPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.04 m/yr | 5 |
| Phosphorus | → Stable | +0.1 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +1.47 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (8 observations).
Estimated open water season: 218 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2007-04-19 (2007) | 2008-04-30 (2008) |
| Ice-In | 2007-11-27 (2007) | 2024-12-01 (2024) |
Most recent ice-out: 2023-04-30
EPA Impairment Status
Unnamed 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 MN56-0437-00 · Official waterbody report · Matched by proximity (1.78 km)
Graded lakes near Unnamed Lake
Unnamed Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Otter Tail County
Frequently asked questions about Unnamed Lake
What is the water quality grade for Unnamed Lake?
- Unnamed Lake in Otter Tail County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 15.1 ft visibility. Phosphorus: 9 µg/L. Chlorophyll-a (algae): 2.6 µg/L. Maximum depth: 95 ft. Surface area: 1356.82 acres.
Is Unnamed Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Unnamed Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 2.6 µg/L. Always check local health department advisories before swimming.
How deep is Unnamed Lake?
- Unnamed Lake has a maximum depth of 95 feet. The lake covers 1356.82 acres.
What fish are in Unnamed Lake?
- Fish species found in Unnamed Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, green sunfish, hybrid sunfish, largemouth bass, longnose gar, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Unnamed Lake is located in Otter Tail County, Minnesota.
When does Unnamed Lake thaw?
- Unnamed Lake typically has ice-out around Apr 25. Ice typically forms around Nov 29. The open water season is approximately 218 days.
Explore Unnamed Lake across LakeGrade
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Where this data comes from
4 measurements from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA4 samples · 2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2120 B ~ Color in Water by Visual Comparison
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
Ice data from Minnesota DNR Climate