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LakeQuality

Sauk Lake

D
Grade D — Nutrient-rich
Nutrient-rich · #16 of 32 lakes in the county · 3.9 ft clear · Eutrophic · 2,126 acres · from C
Eutrophic

Sauk Lake in Stearns County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.9 ft visibility. Phosphorus: 52 µg/L. Chlorophyll-a (algae): 22.3 µg/L. Maximum depth: 61 ft. Surface area: 2125.69 acres.

Clarity
3.9 ft
Max depth
61 ft
Area
2,126 acres
Type
Eutrophic
Trend
Improving
Public access
Yes
Ice-out
Apr 7
Open water
238 days

Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Sauk Lake

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Sauk Lake is a 2,126-acre productive, nutrient-rich eutrophic lake in Stearns County, Minnesota with a maximum depth of 61 feet (17-foot average). Water quality is graded D based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 18 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings. Compared to the 31 other monitored lakes in Stearns County, Sauk Lake ranks #16 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-14. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Algae risk

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.

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum

Compare the safest swimming lakes near Alexandria

Get alerts for Sauk Lake

Water Quality Grade: D (Nutrient-rich)

Murky, only visible to about 3.9 ft. Phosphorus level: 52 µg/L. Chlorophyll-a: 22.3 µg/L. Trophic State Index: 60.

MetricValueGrade
Water Clarity (Secchi Depth)3.9 ftNot graded
Phosphorus52 µg/LPoor
Chlorophyll-a (Algae)22.3 µg/LPoor
Trophic State Index (TSI)60Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Sauk Lake

Compare lakeside cabins, hotels, and vacation rentals near Sauk Lake in Stearns 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Sauk Lake are listed below.

Top-rated places to stay near Sauk 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 →

Lake Details

CharacteristicValue
Maximum Depth61 ft
Average Depth17 ft
Surface Area2,126 acres
Shoreline Length22.3 mi
Littoral Zone65%
Public AccessYes

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Sauk Lake (South)Public
  • Highway 71 BridgePublic

Fish Species

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

Fishing Sauk 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.

flowering rushzebra mussel

DNR Fisheries Survey Summary

29 surveys on file from MN DNR Fisheries. Most recent: 2025-09-09 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Yellow Perch47.090.1 lb
Walleye44.051.33 lb
Bluntnose Minnow40.43
SUN17.15
Bluegill16.700.23 lb
JND15.67

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

2,274 fish · 410 in · 2023-08-14
988494045678910

Walleye

17 fish · 510 in · 2025-09-09
7405678910

Bluegill

148 fish · 310 in · 2023-08-14
67340trophy 10345678910

From the 2025-09-09 survey

Sauk (Big Sauk) Lake (DOW# 77-0150-00; Lake Class 25) is a 2,126-acre lake that extends north of the Sauk Centre Dam. The lake has a maximum depth of 61 feet, an average depth of 17 feet, and water visibility around 6 feet. Sauk Lake has a variety of submerged, emergent, and floating-leaf vegetation around its…

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 Sauk Lake. 3 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 Improving+0.219 m/yr6
Phosphorus Stable-0.3 µg/L/yr2
Chlorophyll-a Improving-2 µg/L/yr2
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (26 observations).

Typical Ice-Out
Apr 7
Typical Ice-In
Dec 1

Estimated open water season: 238 days

EarliestLatest
Ice-Out2016-03-16 (2016)2018-05-01 (2018)
Ice-In2018-11-10 (2018)2017-12-25 (2017)

Most recent ice-out: 2025-04-10

EPA Impairment Status

Sauk Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Impaired biota (cause unknown)MercuryNutrients (phosphorus, nitrogen)

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

Source: EPA ATTAINS assessment unit MN77-0150-01 · Official waterbody report · Matched by proximity (2.4 km)

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Sauk Lake under Clean Water Act (NPDES) discharge permits.

  • Valero-Sauk Centre Terminal
    Sauk Centre · 2.7 mi away · NPDES MN0057771

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

County Ranking

Ranked #16 of 32 lakes in Stearns County

Nearby Lakes With Higher Grades

Sauk Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Stearns County

Frequently asked questions about Sauk Lake

What is the water quality grade for Sauk Lake?

Sauk Lake in Stearns County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.9 ft visibility. Phosphorus: 52 µg/L. Chlorophyll-a (algae): 22.3 µg/L. Maximum depth: 61 ft. Surface area: 2125.69 acres.

Is Sauk Lake safe to swim in?

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Sauk Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 22.3 µg/L. Always check local health department advisories before swimming.

How deep is Sauk Lake?

Sauk Lake has a maximum depth of 61 feet and an average depth of 17 feet. The lake covers 2125.69 acres.

What fish are in Sauk Lake?

Fish species found in Sauk Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Sauk Lake is located in Stearns County, Minnesota.

When does Sauk Lake thaw?

Sauk Lake typically has ice-out around Apr 7. Ice typically forms around Dec 1. The open water season is approximately 238 days.

Are there boat ramps on Sauk Lake?

Sauk Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Sauk Lake (South), Highway 71 Bridge. Public access is listed as yes.

Where this data comes from

343 measurements from 5 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 WaterMNPCA343 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Two Reagent Colorimetry
  • 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
  • 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (5)

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

Regulated discharger data from EPA ECHO (ICIS-NPDES)

Lake details from Minnesota DNR LakeFinder

Named boat-access points from the USGS National Boat Ramps inventory

Ice data from Minnesota DNR Climate