Gunn Lake
Gunn Lake in Itasca County, Minnesota has a water quality grade of B (Good). Water clarity: 14.3 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 3.9 µg/L.
- Clarity
- 14.3 ft
- Typical in August
- 56°F
- Mean depth
- ~17 ft est.
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- Yes
Next lake in Itasca County
Gunn Lake is a cold, clear oligotrophic lake in Itasca County, Minnesota with an estimated average depth of about 17 feet. Water quality is graded B based on 1 sampling years through 2022. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 71 other monitored lakes in Itasca County, Gunn Lake ranks #48 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-09-01. Grade methodology: LakeGrade methodology.
Watch Gunn Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyLimited 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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Good clarity, visible to about 14.3 ft. Phosphorus level: 9.5 µg/L. Chlorophyll-a: 3.9 µg/L. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.3 ft | Not graded |
| Phosphorus | 9.5 µg/L | Good |
| Chlorophyll-a (Algae) | 3.9 µg/L | Not graded |
| Trophic State Index (TSI) | 40 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Gunn Lake
Compare lakeside cabins, hotels, and vacation rentals near Gunn 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 Gunn 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
Gunn Lake typically sits around 56°F at the surface in August. Summer average is about 55°F. Usually warmest in Jul (about 57°F) and coldest in May (about 48°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 210 field readings (2010–2025) via the EPA Water Quality Portal. See the full Gunn Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~17 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Gunn Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Gunn Lake
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Gunn Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Aquatic Plant Report — Fifth Chain (0741)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — Fifth ChainPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.186 m/yr | 5 |
County Ranking
Ranked #48 of 72 lakes in Itasca County
Nearby Lakes in Itasca County
Frequently asked questions about Gunn Lake
What is the water quality grade for Gunn Lake?
- Gunn Lake in Itasca County, Minnesota has a water quality grade of B (Good). Water clarity: 14.3 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 3.9 µg/L.
Is Gunn Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Gunn Lake has a water quality grade of B (Good). Algae concentration (chlorophyll-a) is 3.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Gunn Lake?
- Gunn Lake typically sits around 56°F at the surface in August, from 210 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Gunn Lake?
- No published bathymetric survey covers Gunn Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 17 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Gunn Lake across LakeGrade
Fish species and top-graded 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 grade
Lakes in the Mississippi Headwaters, ranked by water quality
Lakes in the Rainy Lake Watershed, ranked by water quality
Low nutrients, clear water, excellent for swimming
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Gunn Lake
Other Grade B Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Where this data comes from
33 measurements from 2 monitoring stations, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA33 samples · 2020–2022
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder