Loon Lake
Itasca County, Minnesota231 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Loon Lake. Here is what has been measured.
- Impaired · Mercury
- 69 ft max depth
- Public access
- Limited data
Loon Lake in Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14 ft visibility. Maximum depth: 69 ft. Surface area: 230.99 acres.
Minnesota DNR's Standard Survey on June 5, 2017 caught 0.20 walleye per gill net at Loon Lake. DNR survey details →
Loon Lake is a 231-acre lake in Itasca County, Minnesota with a maximum depth of 69 feet. Overall water quality is improving over recent sampling years. The lake supports 12 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-08-20. Methodology: how these readings are compared.
What Loon Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14 ft of visibility
- Boat launch1 documented ramp
- Fishing12 species recorded
- Ice seasonIce-out around Apr 18
- Deep water69 ft surveyed max depth
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Loon Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Loon Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Loon Lake
These are the measurements Minnesota PCA publishes for Loon Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 14 ft. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Loon Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on June 5, 2017 caught 0.20 walleye per gill net at Loon Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Loon Lake’s water-quality measurements separately, 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
8 surveys on file from MN DNR Fisheries. Most recent: 2025-08-06 (Targeted Survey).
8 surveys on file · most recent 2025-08-06 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 25.82 | 3–8 in 2017-06-05 | 0.12 lb |
| Largemouth Bass | 13.83 | 5–17 in 2017-06-05 | 1.14 lb |
| Tullibee (Cisco) | 11.73 | 13–17 in 2017-06-05 | 1.21 lb |
| Yellow Perch | 6.70 | 5–8 in 2017-06-05 | 0.14 lb |
| Pumpkinseed | 3.99 | 3–7 in 2017-06-05 | 0.19 lb |
| Northern Pike | 3.91 | 15–37 in 2017-06-05 | 2.05 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and 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
Largemouth Bass
Tullibee (Cisco)
Yellow Perch
From the 2025-08-06 survey
Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Loon Lake on August 6th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Loon Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — LoonFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Loon (0558)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — LoonPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
69 ft
Surface area
231 acres
Shoreline
3.6 mi
Littoral zone
48%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,273 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Loon LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Loon Lake
Compare lakeside cabins, hotels, and vacation rentals near Loon Lake in Itasca 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 Loon Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
Follow Loon Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Loon Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Ice season
Typical ice-out
Apr 18
Earliest Mar 25, 2012 · Latest May 14, 2013
Typical ice-in
Nov 26
Earliest Nov 12, 2002 · Latest Dec 7, 2001
Most recent ice-out
Apr 5
2021
34 observations · Minnesota PCA ice records
EPA Impairment Status
Loon Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN31-0571-00 · Official waterbody report
Nearby Lakes in Itasca County
Frequently asked questions about Loon Lake
Where is Loon Lake?
- Loon Lake is a lake in Itasca County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Loon Lake?
- Loon Lake in Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14 ft visibility. Maximum depth: 69 ft. Surface area: 230.99 acres.
Is Loon Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Loon Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is Loon Lake?
- Loon Lake has a maximum depth of 69 feet. The lake covers 230.99 acres.
What fish are in Loon Lake?
- Fish species found in Loon Lake include black crappie, bluegill, bowfin (dogfish), hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, yellow bullhead, yellow perch. Loon Lake is located in Itasca County, Minnesota.
What did the DNR fisheries survey find at Loon Lake?
- Minnesota DNR's Standard Survey on June 5, 2017 caught 0.20 walleye per gill net at Loon Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Loon Lake’s water-quality measurements separately, 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 Loon Lake thaw?
- Loon Lake typically has ice-out around Apr 18. Ice typically forms around Nov 26. The open water season is approximately 222 days.
Are there boat ramps on Loon Lake?
- Loon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Loon Lake. Public access is listed as yes.
Can I fish at Loon Lake?
- Loon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Loon Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Itasca County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Mississippi Headwaters, ranked by water quality
Lakes in the Rainy Lake Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Loon Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Where this data comes from
4 measurements from 2 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA4 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (2)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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