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LakeQuality

Holly Lake

NR
Not yet rated
4.5 ft clear · Eutrophic · 76 acres
Limited DataEutrophic

Holly Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.5 ft visibility. Maximum depth: 6 ft. Surface area: 75.94 acres.

Clarity
4.5 ft
Max depth
6 ft
Area
76 acres
Trend
Declining
Public access
Yes
Ice-out
May 8
Open water
187 days

Next lake in Cook County

AClara Lake7.6 ft clear · Cook CountyView →
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Why Holly 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 Holly 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.

Holly Lake is a 76-acre lake in Cook County, Minnesota with a maximum depth of 6 feet. Overall water quality is declining over recent sampling years. The lake supports 5 documented fish species including northern pike, pumpkinseed, and walleye. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-13. 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 Ely

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Water quality measurements for Holly Lake

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

Murky, only visible to about 4.5 ft. Trophic State Index: 55.

MetricValueGrade
Water Clarity (Secchi Depth)4.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)55Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Holly Lake

Compare lakeside cabins, hotels, and vacation rentals near Holly 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 Holly 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 Depth6 ft
Surface Area76 acres
Shoreline Length1.8 mi
Littoral Zone100%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
5 sq mi
Elevation
1,624 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Holly LakePublic

Fish Species

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

Fishing Holly Lake

DNR Fisheries Survey Summary

10 surveys on file from MN DNR Fisheries. Most recent: 2023-07-05 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Yellow Perch27.510.14 lb
White Sucker8.881.75 lb
GOS7.360.08 lb
BND4.58
Walleye4.411.58 lb
Northern Pike3.701.8 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

80 fish · 110 in · 2023-07-05
2814012345678910

White Sucker

71 fish · 820 in · 2023-07-05
1160891011121314151617181920

GOS

1 fish · 66 in · 2023-07-05
106

Walleye

19 fish · 323 in · 2023-07-05
420trophy 2446810121416182022

From the 2023-07-05 survey

Holly is 75-acre lake located about 11 miles north of Lutsen. Public access is through a boat landing on the southeast bay of the lake. Holly has historically been managed for walleye with supplemental stocking since the 1970s. Walleye stocking was discontinued in 2018 after survey results showed a healthy naturally…

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 Holly Lake. 4 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-0.086 m/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (11 observations).

Typical Ice-Out
May 8
Typical Ice-In
Nov 11

Estimated open water season: 187 days

EarliestLatest
Ice-Out2020-05-02 (2020)2022-05-14 (2022)
Ice-In2017-11-01 (2017)2024-11-25 (2024)

Most recent ice-out: 2023-05-11

EPA Impairment Status

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

Causes of impairment

Mercury

Source: EPA ATTAINS assessment unit MN16-0366-00 · Official waterbody report

Graded lakes near Holly Lake

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

Nearby Lakes in Cook County

Frequently asked questions about Holly Lake

What is the water quality grade for Holly Lake?

Holly Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.5 ft visibility. Maximum depth: 6 ft. Surface area: 75.94 acres.

Is Holly Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Holly Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

How deep is Holly Lake?

Holly Lake has a maximum depth of 6 feet. The lake covers 75.94 acres.

What fish are in Holly Lake?

Fish species found in Holly Lake include northern pike, pumpkinseed, walleye, white sucker, yellow perch. Holly Lake is located in Cook County, Minnesota.

When does Holly Lake thaw?

Holly Lake typically has ice-out around May 8. Ice typically forms around Nov 11. The open water season is approximately 187 days.

Are there boat ramps on Holly Lake?

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

Where this data comes from

40 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 WaterMNPCA40 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

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

Ice data from Minnesota DNR Climate