Turtle Lake
Turtle Lake in Becker County, Minnesota has a water quality grade of A (Excellent). Water clarity: 23 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 73 ft. Surface area: 196.39 acres.
Minnesota DNR surveys at Turtle Lake average 35.76 bluegill per unit of sampling effort (CPUE) across 10 surveys. The most recent is a Standard Survey dated June 29, 2020. Length samples in the latest survey that recorded them ran 2–9 inches. DNR survey details →
- Clarity
- 23 ft
- Typical in August
- 74°F
- Max depth
- 73 ft
- Area
- 196 acres
- Type
- Oligotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 17
- Open water
- 224 days
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Turtle Lake is a 196-acre cold, clear oligotrophic lake in Becker County, Minnesota with a maximum depth of 73 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 13 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings. Compared to the 83 other monitored lakes in Becker County, Turtle Lake ranks #13 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-19. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyLow algae
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Crystal clear, you can see 23 ft down. Phosphorus level: 8 µg/L. Chlorophyll-a: 1.9 µg/L. Trophic State Index: 34.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 23 ft | Not graded |
| Phosphorus | 8 µg/L | Good |
| Chlorophyll-a (Algae) | 1.9 µg/L | Good |
| Trophic State Index (TSI) | 34 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Turtle Lake
Compare lakeside cabins, hotels, and vacation rentals near Turtle Lake in Becker 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.
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Water Temperature
Turtle Lake typically sits around 74°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in Sep (about 69°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 111 field readings (2011–2025) via the EPA Water Quality Portal. See the full Turtle Lake water temperature breakdown →
Minnesota DNR surveys at Turtle Lake average 35.76 bluegill per unit of sampling effort (CPUE) across 10 surveys. The most recent is a Standard Survey dated June 29, 2020. Length samples in the latest survey that recorded them ran 2–9 inches.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Turtle Lake A from EPA Water Quality Portal chemistry, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2020-06-29 (Standard Survey).
Top Species by Catch Rate
| Species | Avg catch rate (CPUE) | Avg Weight |
|---|---|---|
| Bluegill | 35.76 | 0.2 lb |
| Yellow Perch | 20.81 | 0.18 lb |
| Black Crappie | 12.11 | 0.51 lb |
| Hybrid Sunfish | 9.88 | 0.26 lb |
| Bluntnose Minnow | 9.29 | — |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE means more abundant in standardized sampling. This is not a weekly bite report.
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
Yellow Perch
Black Crappie
Hybrid Sunfish
From the 2020-06-29 survey
Turtle Lake is a 196-acre lake located in western Becker County. The lake possesses a heavily developed shoreline and receives significant recreational use and angling pressure. Lake survey assessments are completed periodically on Turtle Lake to highlight and track changes in species presence and abundance over time.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Turtle Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — TurtleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Turtle (1018)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — TurtleFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — TurtlePublic Water Access Sites · MN DNR LakeFinder
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 73 ft |
| Surface Area | 196 acres |
| Shoreline Length | 2.5 mi |
| Littoral Zone | 36% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Turtle LakePublic
- Lake FifteenPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Turtle 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.
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.093 m/yr | 6 |
| Phosphorus | → Stable | +0.04 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.15 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (64 observations).
Estimated open water season: 224 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 1987-04-09 (1987) | 1979-05-06 (1979) |
| Ice-In | 1997-11-10 (1997) | 2002-12-20 (2002) |
Most recent ice-out: 2015-04-12
County Ranking
Ranked #13 of 84 lakes in Becker County
Nearby Lakes in Becker County
Frequently asked questions about Turtle Lake
Where is Turtle Lake?
- Turtle Lake is a lake in Becker County, Minnesota. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Turtle Lake?
- Turtle Lake in Becker County, Minnesota has a water quality grade of A (Excellent). Water clarity: 23 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 73 ft. Surface area: 196.39 acres.
Is Turtle Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Turtle Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 1.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Turtle Lake?
- Turtle Lake typically sits around 74°F at the surface in August, from 111 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Turtle Lake?
- Turtle Lake has a maximum depth of 73 feet. The lake covers 196.39 acres.
What fish are in Turtle Lake?
- Fish species found in Turtle Lake include black bullhead, black crappie, bluegill, brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow perch. Turtle Lake is located in Becker County, Minnesota.
What did the DNR fisheries survey find at Turtle Lake?
- Minnesota DNR surveys at Turtle Lake average 35.76 bluegill per unit of sampling effort (CPUE) across 10 surveys. The most recent is a Standard Survey dated June 29, 2020. Length samples in the latest survey that recorded them ran 2–9 inches. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Turtle Lake A from EPA Water Quality Portal chemistry, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Turtle Lake thaw?
- Turtle Lake typically has ice-out around Apr 17. Ice typically forms around Nov 27. The open water season is approximately 224 days.
Are there boat ramps on Turtle Lake?
- Turtle Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Turtle Lake, Lake Fifteen. Public access is listed as yes.
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Where this data comes from
250 measurements from 3 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 Water
MNPCA250 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 (3)
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
Ice data from Minnesota DNR Climate