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LakeQuality

Tom Lake

A
Grade A — Excellent
Excellent · #15 of 44 lakes in the county · 9 ft clear · Mesotrophic · 404 acres · from B
Mesotrophic

Tom Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Water clarity: 9 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 4.1 µg/L. Maximum depth: 35 ft. Surface area: 404.48 acres.

Clarity
9 ft
Typical in August
70°F
Max depth
35 ft
Area
404 acres
Type
Mesotrophic
Trend
Declining
Public access
Yes
Ice-out
May 2

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ATrout Lake18.4 ft clear · Cook CountyView →
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Tom Lake is a 404-acre mesotrophic lake in Cook County, Minnesota with a maximum depth of 35 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 5 documented fish species including burbot, lake whitefish, and walleye. Public access is available with 1 public boat landing. Compared to the 43 other monitored lakes in Cook County, Tom Lake ranks #15 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

Low 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

Compare the safest swimming lakes near Ely

Get alerts for Tom Lake

Water Quality Grade: A (Excellent)

Moderate clarity, visible to about 9 ft. Phosphorus level: 8 µg/L. Chlorophyll-a: 4.1 µg/L. Trophic State Index: 41.

MetricValueGrade
Water Clarity (Secchi Depth)9 ftNot graded
Phosphorus8 µg/LGood
Chlorophyll-a (Algae)4.1 µg/LGood
Trophic State Index (TSI)41Mesotrophic

Moderate nutrients, good water quality

Where to stay near Tom Lake

Compare lakeside cabins, hotels, and vacation rentals near Tom Lake in Cook 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 Tom 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

Tom Lake typically sits around 70°F at the surface in August. Summer average is about 65°F. Usually warmest in Aug (about 70°F) and coldest in May (about 50°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
50°
Jun
Jul
60°
Aug
70°
Sep
Oct
52°
Nov
Dec

Typical surface water temperature by month, from 23 field readings (20222025) via the EPA Water Quality Portal. See the full Tom Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth35 ft
Surface Area404 acres
Shoreline Length8.2 mi
Littoral Zone83%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
7 sq mi
Elevation
1,627 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Tom LakePublic

Fish Species

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

Fishing Tom Lake

DNR Fisheries Survey Summary

10 surveys on file from MN DNR Fisheries. Most recent: 2023-07-17 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Yellow Perch13.030.18 lb
Walleye3.981.09 lb
White Sucker2.521.8 lb
LKW2.453.43 lb
CRC1.080.08 lb
Northern Pike0.711.14 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.

Yellow Perch

44 fish · 510 in · 2023-07-17
17905678910

Walleye

43 fish · 826 in · 2023-07-17
840trophy 248101214161820222426

White Sucker

30 fish · 619 in · 2023-07-17
840678910111213141516171819

LKW

13 fish · 1424 in · 2023-07-17
5301415161718192021222324

From the 2023-07-17 survey

Tom Lake is a 404 acre lake located approximately 7 miles northwest of Hovland. Public access is through a boat landing on the northwest side of the lake. Tom Lake part of the Lake Superior North watershed and is the headwater lake of the Swamp River. Tom Lake is primarily managed for walleye. The 2023 standard lake…

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 Tom 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 Declining-0.101 m/yr6
Phosphorus Declining+0.8 µg/L/yr5
Chlorophyll-a Declining+0.82 µg/L/yr5
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (3 observations).

Typical Ice-Out
May 2
EarliestLatest
Ice-Out2007-04-28 (2007)2022-05-17 (2022)

Most recent ice-out: 2022-05-17

EPA Impairment Status

Tom 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 MN16-0019-00 · Official waterbody report

County Ranking

Ranked #15 of 44 lakes in Cook County

Nearby Lakes in Cook County

Frequently asked questions about Tom Lake

What is the water quality grade for Tom Lake?

Tom Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Water clarity: 9 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 4.1 µg/L. Maximum depth: 35 ft. Surface area: 404.48 acres.

Is Tom Lake safe to swim in?

Excellent for swimming, crystal clear water with minimal algae. Tom Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4.1 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Tom Lake?

Tom Lake typically sits around 70°F at the surface in August, from 23 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.

How deep is Tom Lake?

Tom Lake has a maximum depth of 35 feet. The lake covers 404.48 acres.

What fish are in Tom Lake?

Fish species found in Tom Lake include burbot, lake whitefish, walleye, white sucker, yellow perch. Tom Lake is located in Cook County, Minnesota.

When does Tom Lake thaw?

Tom Lake typically has ice-out around May 2.

Are there boat ramps on Tom Lake?

Tom Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Tom Lake. Public access is listed as yes.

Where this data comes from

145 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 WaterMNPCA145 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

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