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LakeQuality

Turtle River Lake

C
Grade C — Fair
Fair · #70 of 85 lakes in the county · 8.5 ft clear · Mesotrophic · 1,740 acres · from B
Mesotrophic

Turtle River Lake in Beltrami County, Minnesota has a water quality grade of C (Fair). Water clarity: 8.5 ft visibility. Phosphorus: 18.5 µg/L. Chlorophyll-a (algae): 7.5 µg/L. Maximum depth: 63 ft. Surface area: 1740.29 acres.

Clarity
8.5 ft
Max depth
63 ft
Area
1,740 acres
Type
Mesotrophic
Trend
Improving
Public access
Yes
Ice-out
Apr 22
Open water
218 days

Next lake in Beltrami County

ALong Lake20 ft clear · Beltrami CountyView →
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Free interactive depth-contour map of Turtle River Lake, reaching a maximum surveyed depth of 60 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.

Turtle River Lake is a 1,740-acre mesotrophic lake in Beltrami County, Minnesota with a maximum depth of 63 feet (20-foot average). Water quality is graded C based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 20 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings. Compared to the 84 other monitored lakes in Beltrami County, Turtle River Lake ranks #70 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Moderate

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Generally safe for swimming, moderate water quality

Compare the safest swimming lakes near Bemidji

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Water Quality Grade: C (Fair)

Moderate clarity, visible to about 8.5 ft. Phosphorus level: 18.5 µg/L. Chlorophyll-a: 7.5 µg/L. Trophic State Index: 48.

MetricValueGrade
Water Clarity (Secchi Depth)8.5 ftNot graded
Phosphorus18.5 µg/LGood
Chlorophyll-a (Algae)7.5 µg/LFair
Trophic State Index (TSI)48Mesotrophic

Moderate nutrients, good water quality

Where to stay near Turtle River Lake

Compare lakeside cabins, hotels, and vacation rentals near Turtle River Lake in Beltrami 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 Turtle River Lake

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Planning a whole trip? See where to stay at Minnesota’s top lakes →

Lake Details

CharacteristicValue
Maximum Depth63 ft
Average Depth20 ft
Surface Area1,740 acres
Shoreline Length17.3 mi
Littoral Zone38%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
124 sq mi
Elevation
1,296 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Turtle River Lake (West)Public
  • Turtle River Lake (North)Public

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Turtle 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.

starry stonewortzebra mussel

DNR Fisheries Survey Summary

11 surveys on file from MN DNR Fisheries. Most recent: 2023-08-10 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
CNM24.22
Yellow Perch23.840.13 lb
BKF19.99
JND16.52
Bluntnose Minnow13.04
TRP5.88

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.

Yellow Perch

270 fish · 49 in · 2021-08-31
123620456789

From the 2023-08-10 survey

A temperature-dissolved oxygen profile was collected in three of the deepest basins on Turtle River Lake on August 10, 2023, to evaluate the amount of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee. Based on the profiles, the top of the thermocline (i.e., the location in…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Turtle River Lake. 4 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Stable-0.031 m/yr6
Phosphorus Stable+0.03 µg/L/yr6
Chlorophyll-a Improving-0.3 µg/L/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (23 observations).

Typical Ice-Out
Apr 22
Typical Ice-In
Nov 26

Estimated open water season: 218 days

EarliestLatest
Ice-Out2012-03-31 (2012)2013-05-14 (2013)
Ice-In2019-11-08 (2019)2006-12-01 (2006)

Most recent ice-out: 2024-04-03

EPA Impairment Status

Turtle River Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Mercury

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN04-0111-00 · Official waterbody report

County Ranking

Ranked #70 of 85 lakes in Beltrami County

Nearby Lakes With Higher Grades

Turtle River Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Beltrami County

Frequently asked questions about Turtle River Lake

What is the water quality grade for Turtle River Lake?

Turtle River Lake in Beltrami County, Minnesota has a water quality grade of C (Fair). Water clarity: 8.5 ft visibility. Phosphorus: 18.5 µg/L. Chlorophyll-a (algae): 7.5 µg/L. Maximum depth: 63 ft. Surface area: 1740.29 acres.

Is Turtle River Lake safe to swim in?

Generally safe for swimming, moderate water quality. Turtle River Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 7.5 µg/L. Always check local health department advisories before swimming.

How deep is Turtle River Lake?

Turtle River Lake has a maximum depth of 63 feet and an average depth of 20 feet. The lake covers 1740.29 acres.

What fish are in Turtle River Lake?

Fish species found in Turtle River Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, burbot, hybrid sunfish, lake whitefish, largemouth bass, northern pike, northern sunfish, pumpkinseed, redhorse, rock bass, shorthead redhorse, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Turtle River Lake is located in Beltrami County, Minnesota.

When does Turtle River Lake thaw?

Turtle River Lake typically has ice-out around Apr 22. Ice typically forms around Nov 26. The open water season is approximately 218 days.

Are there boat ramps on Turtle River Lake?

Turtle River Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Turtle River Lake (West), Turtle River Lake (North). Public access is listed as yes.

State Parks Near Turtle River Lake

Where this data comes from

79 measurements from 2 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 WaterMNPCA79 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 (2)

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

Ice data from Minnesota DNR Climate