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LakeQuality

Turtle Lake

NR
Not yet rated
8.6 ft clear · Mesotrophic · 108 acres
Limited DataMesotrophic

Turtle Lake in Crow Wing County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.6 ft visibility. Maximum depth: 33 ft. Surface area: 108.21 acres.

Clarity
8.6 ft
Typical in August
76°F
Max depth
33 ft
Area
108 acres
Trend
Declining
Public access
No

Next lake in Crow Wing County

ABay Lake18.5 ft clear · Crow Wing CountyView →
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Why Turtle 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 Turtle 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.

Turtle Lake is a 108-acre lake in Crow Wing County, Minnesota with a maximum depth of 33 feet. Overall water quality is declining over recent sampling years. The lake supports 8 documented fish species including black crappie, bluegill, and brown bullhead. No public access — the lake is private or restricted.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-08-31. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Brainerd

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Water quality measurements for Turtle Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Moderate clarity, visible to about 8.6 ft. Trophic State Index: 46.

MetricValueGrade
Water Clarity (Secchi Depth)8.6 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)46Mesotrophic

Moderate nutrients, good water quality

Where to stay near Turtle Lake

Compare lakeside cabins, hotels, and vacation rentals near Turtle Lake in Crow Wing 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 Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

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

Water Temperature

Turtle Lake typically sits around 76°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 76°F) and coldest in Jun (about 71°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
Jun
71°
Jul
76°
Aug
76°
Sep
Oct
Nov
Dec

Typical surface water temperature by month, from 12 field readings (20232025) via the EPA Water Quality Portal. See the full Turtle Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth33 ft
Surface Area108 acres
Shoreline Length2.7 mi
Littoral Zone72%
Public AccessNo

Lake Size & Watershed

Watershed (drainage) area
0 sq mi
Elevation
1,263 ft

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

Fish Species

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

Fishing Turtle Lake

DNR Fisheries Survey Summary

3 surveys on file from MN DNR Fisheries. Most recent: 2023-08-02 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
BCS61.93
Bluegill36.800.07 lb
GOS36.48
JND31.97
BNS18.89
Yellow Bass16.200.34 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

112 fish · 27 in · 2023-07-31
60300234567

Yellow Bass

119 fish · 413 in · 2023-07-31
2814045678910111213

From the 2023-08-02 survey

Turtle is a 108 acre lake, with a maximum depth of 33', located 3.5 miles North of Garrison, MN. Turtle is in the Rum River Watershed. A nearshore survey was conducted to assess the populations of both game and non-game fish species. Ten 100' long sampling stations were evenly spaced around the lakeshore. Each station…

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 Lake. 2 reports on file.

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

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.264 m/yr5
See year-by-year chart →

EPA Impairment Status

Turtle 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 MN01-0204-00 · Official waterbody report · Matched by proximity (2.38 km)

Graded lakes near Turtle Lake

Turtle Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Crow Wing County

Frequently asked questions about Turtle Lake

What is the water quality grade for Turtle Lake?

Turtle Lake in Crow Wing County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.6 ft visibility. Maximum depth: 33 ft. Surface area: 108.21 acres.

Is Turtle Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Turtle 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 Turtle Lake?

Turtle Lake typically sits around 76°F at the surface in August, from 12 EPA Water Quality Portal field readings (2023–2025). That is a typical value for the month, not a live reading.

How deep is Turtle Lake?

Turtle Lake has a maximum depth of 33 feet. The lake covers 108.21 acres.

What fish are in Turtle Lake?

Fish species found in Turtle Lake include black crappie, bluegill, brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, yellow bullhead. Turtle Lake is located in Crow Wing County, Minnesota.

Where this data comes from

20 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 WaterMNPCA20 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

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder