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LakeQuality

Pine Lake

A
Grade A — Excellent
Excellent · #10 of 68 lakes in the county · 7.5 ft clear · Mesotrophic · 450 acres · from B
Limited DataMesotrophic

Pine Lake in St. Louis County, Minnesota has a water quality grade of A (Excellent). Water clarity: 7.5 ft visibility. Phosphorus: 15.5 µg/L. Chlorophyll-a (algae): 3.9 µg/L. Maximum depth: 14 ft. Surface area: 450.07 acres.

Clarity
7.5 ft
Typical in August
69°F
Max depth
14 ft
Area
450 acres
Type
Mesotrophic
Public access
Yes

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Pine Lake is a 450-acre mesotrophic lake in St. Louis County, Minnesota with a maximum depth of 14 feet. Water quality is graded A based on 2 sampling years through 2020. The lake supports 8 documented fish species including bluegill, hybrid sunfish, and northern pike. Public access is available. Compared to the 67 other monitored lakes in St. Louis County, Pine Lake ranks #10 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-09-14. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Limited data

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

Compare the safest swimming lakes near Ely

Get alerts for Pine Lake

Water Quality Grade: A (Excellent)

Moderate clarity, visible to about 7.5 ft. Phosphorus level: 15.5 µg/L. Chlorophyll-a: 3.9 µg/L. Trophic State Index: 45.

MetricValueGrade
Water Clarity (Secchi Depth)7.5 ftNot graded
Phosphorus15.5 µg/LGood
Chlorophyll-a (Algae)3.9 µg/LGood
Trophic State Index (TSI)45Mesotrophic

Moderate nutrients, good water quality

Where to stay near Pine Lake

Compare lakeside cabins, hotels, and vacation rentals near Pine Lake in St. Louis 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 Pine 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

Pine Lake typically sits around 69°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 76°F) and coldest in May (about 52°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
52°
Jun
Jul
76°
Aug
69°
Sep
63°
Oct
Nov
Dec

Typical surface water temperature by month, from 16 field readings (20192019) via the EPA Water Quality Portal. See the full Pine Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth14 ft
Surface Area450 acres
Shoreline Length4.1 mi
Littoral Zone100%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
7 sq mi
Elevation
1,696 ft

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

Fish Species

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

Fishing Pine Lake

DNR Fisheries Survey Summary

5 surveys on file from MN DNR Fisheries. Most recent: 2017-06-26 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluegill16.920.26 lb
Yellow Perch9.680.21 lb
Pumpkinseed5.050.15 lb
Northern Pike4.611.94 lb
Walleye3.181.88 lb
White Sucker1.162.83 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

187 fish · 18 in · 2017-06-26
8141012345678

Yellow Perch

36 fish · 59 in · 2017-06-26
126056789

Pumpkinseed

57 fish · 47 in · 2017-06-26
351804567

Northern Pike

62 fish · 1042 in · 2017-06-26
1050trophy 361012141618202224262830323436384042

From the 2017-06-26 survey

Pine Lake is in Ecological Lake Class 16, which consists of 38 lakes in northeast Minnesota that are large, shallow, and have bog-stained and soft (unmineralized) water. Lake bottom substrates along the shoreline are 30% sand, 30% gravel, 20% boulder, 17% rubble, and 3% muck. Aquatic plants grow to a depth of 4 ft;…

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 Pine Lake. 3 reports on file.

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

EPA Impairment Status

Pine 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 MN69-0001-00 · Official waterbody report

County Ranking

Ranked #10 of 68 lakes in St. Louis County

Nearby Lakes in St. Louis County

Frequently asked questions about Pine Lake

What is the water quality grade for Pine Lake?

Pine Lake in St. Louis County, Minnesota has a water quality grade of A (Excellent). Water clarity: 7.5 ft visibility. Phosphorus: 15.5 µg/L. Chlorophyll-a (algae): 3.9 µg/L. Maximum depth: 14 ft. Surface area: 450.07 acres.

Is Pine Lake safe to swim in?

Excellent for swimming, crystal clear water with minimal algae. Pine Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.9 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Pine Lake?

Pine Lake typically sits around 69°F at the surface in August, from 16 EPA Water Quality Portal field readings (2019–2019). That is a typical value for the month, not a live reading.

How deep is Pine Lake?

Pine Lake has a maximum depth of 14 feet. The lake covers 450.07 acres.

What fish are in Pine Lake?

Fish species found in Pine Lake include bluegill, hybrid sunfish, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow perch. Pine Lake is located in St. Louis County, Minnesota.

Where this data comes from

15 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA15 samples · 2020

Analytical methods

  • Field measurement/observation, generic method
  • 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
  • 10200 H ~ Chlorophyll a-b-c Determination
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