Deer Lake
Otter Tail County, MinnesotaMesotrophic
Deer Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. clarity and phosphorus rate similarly, so there is no obvious single lever to pull on watershed management.
A TSI near 45 places Deer Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 26 ft puts Deer Lake in the middle of Minnesota's depth distribution. The lake's 447 acres and 3.9 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Deer Lake ranks 47 of 97 in Otter Tail County — solidly in the upper half of the local distribution.
Zebra mussel presence at Deer Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. The fishery includes walleye among the lake's 16 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 8 observed ice-outs, centered near Apr 20. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-15. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 11.5 ft. Phosphorus level: 21 µg/L. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | B |
| Phosphorus | 21 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 26 ft |
| Surface Area | 447.07 acres |
| Shoreline Length | 3.9 mi |
| Littoral Zone | 68% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Deer Lake (14-day solunar calendar)
→ Is it safe to eat fish from Deer Lake? (mercury & PFAS guide)
→ Deer Lake fishing regulations (limits, seasons, special rules)
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 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.168 m/yr | 5 |
| Phosphorus | → Stable | -0.35 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (13 observations).
Estimated open water season: 218 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-15 (2024) | 2023-04-30 (2023) |
| Ice-In | 2018-11-10 (2018) | 2016-12-07 (2016) |
Most recent ice-out: 2024-03-15
Location
County Ranking
Ranked #47 of 97 lakes in Otter Tail County
Cleaner Lakes Within 30 Miles
Deer Lake holds Grade B. 5 nearby lakes hold higher grades.
- AElbow LakeOtter Tail County · mi · Higher grade (B → A)
- ARound LakeOtter Tail County · mi · Higher grade (B → A)
- ASilver LakeOtter Tail County · mi · Higher grade (B → A)
- APickerel LakeOtter Tail County · mi · Higher grade (B → A)
- ABlanche LakeOtter Tail County · mi · Higher grade (B → A)
Nearby Lakes in Otter Tail County
More Minnesota Lake Rankings
State Parks Near Deer Lake
Other Grade B Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Compare Deer Lake With Nearby Lakes
Otter Tail County · Grade A
Otter Tail County · Grade C
Otter Tail County · Grade B
Otter Tail County · Grade D
Otter Tail County · Grade A
Otter Tail County · Grade A
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2024-06-10 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 25.12 | 0.12 lb |
| Largemouth Bass | 9.66 | 0.78 lb |
| Pumpkinseed | 4.68 | 0.17 lb |
| Yellow Perch | 3.78 | 0.2 lb |
| Northern Pike | 3.33 | 1.06 lb |
| Yellow Bass | 3.31 | 0.73 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
Largemouth Bass
Pumpkinseed
Yellow Perch
From the 2024-06-10 survey
Deer Lake is a 457-acre mesotrophic (moderately fertile) lake located in central Otter Tail County approximately five miles north of Battle Lake, MN. Deer Lake is connected to Otter Tail Lake via the Otter Tail River. The immediate watershed is composed primarily of agricultural land interspersed with hardwood…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Deer Lake. 4 reports on file.
- —Fisheries Lake Survey — DeerFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Deer (1164)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — DeerFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — DeerPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Deer Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN56-0378-01 · Official waterbody report · Matched by proximity (1.33 km)
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate
Most recent sample: 2024-09-15
Monitoring stations: 1