Gull Lake
Gull Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 15 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 3 µg/L. Maximum depth: 80 ft. Surface area: 10009.97 acres.
- Clarity
- 15 ft
- Max depth
- 80 ft
- Area
- 10,010 acres
- Type
- Mesotrophic
- Public access
- Yes
- Ice-out
- Apr 21
- Open water
- 224 days
Next lake in Cass County
Free interactive depth-contour map of Gull Lake, reaching a maximum surveyed depth of 80 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Gull Lake is a 10,010-acre mesotrophic lake in Cass County, Minnesota with a maximum depth of 80 feet. Water quality is graded A based on 2 sampling years through 2025. The lake supports 22 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 103 other monitored lakes in Cass County, Gull Lake ranks #20 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-28. Grade methodology: LakeGrade methodology.
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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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Crystal clear, you can see 15 ft down. Phosphorus level: 13.5 µg/L. Chlorophyll-a: 3 µg/L. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15 ft | Not graded |
| Phosphorus | 13.5 µg/L | Good |
| Chlorophyll-a (Algae) | 3 µg/L | Good |
| Trophic State Index (TSI) | 40 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Gull Lake
Compare lakeside cabins, hotels, and vacation rentals near Gull Lake in Cass 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 Gull Lake
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Planning a trip? Cabins and lodging at Gull Lake → · more Minnesota lake trips
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Gull Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (15,704 cells/mL) on November 22, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 80 ft |
| Surface Area | 10,010 acres |
| Shoreline Length | 46.1 mi |
| Littoral Zone | 28% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Government PointPublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Gull Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
37 surveys on file from MN DNR Fisheries. Most recent: 2025-09-23 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Yellow Perch | 51.50 | 0.11 lb |
| Walleye | 31.64 | 1.24 lb |
| Largemouth Bass | 16.07 | 0.89 lb |
| Bluegill | 14.44 | 0.14 lb |
| Northern Pike | 11.66 | 3.38 lb |
| LND | 11.25 | — |
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
Walleye
Largemouth Bass
Bluegill
From the 2025-09-23 survey
Gull Lake is normally stocked annually with Walleye fry at the rate of 1,000 per littoral acre (2,825,000 fry). Fingerlings are stocked on a contingency basis if fall electrofishing results are less than 30 young-of-the-year (YOY) Walleye per hour for two consecutive years; fingerlings were last stocked in the fall of…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Gull Lake. 5 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — GullFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Gull (1532)Aquatic Plant Report · MN DNR LakeFinder
- —Aquatic Plant Report — Gull (1539)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — GullFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — GullPublic Water Access Sites · MN DNR LakeFinder
Ice Season
Historical ice data from Minnesota DNR (138 observations).
Estimated open water season: 224 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-17 (2024) | 1950-05-18 (1950) |
| Ice-In | 1959-11-14 (1959) | 1998-12-22 (1998) |
Most recent ice-out: 2025-04-18
Reservoir Info (USACE NID)
Gull Lake is a man-made reservoir impounded by the Gull Dam (completed 1912), built primarily for recreation on the GULL RIVER; concrete-type dam, 15 ft tall and 276 ft long.
- Surface area
- 13,000 ac
- Normal storage
- 61,000 ac-ft
- Max storage
- 75,300 ac-ft
- Drainage area
- 287 sq mi
- Hazard class
- Low
- Owner
- USACE - St. Paul District
All listed purposes: Recreation;Other;Navigation;Fish and Wildlife Pond;Water Supply;Flood Risk Reduction.
Source: USACE National Inventory of Dams, NID ID MN00596 · Operator website
EPA Impairment Status
Gull Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN11-0305-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Gull Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- East Gull Lake WwtpEast Gull Lake · 2 mi away · NPDES MN0059871Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #20 of 104 lakes in Cass County
Nearby Lakes in Cass County
Frequently asked questions about Gull Lake
What is the water quality grade for Gull Lake?
- Gull Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 15 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 3 µg/L. Maximum depth: 80 ft. Surface area: 10009.97 acres.
Is Gull Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Gull Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3 µg/L. Always check local health department advisories before swimming.
How deep is Gull Lake?
- Gull Lake has a maximum depth of 80 feet. The lake covers 10009.97 acres.
What fish are in Gull Lake?
- Fish species found in Gull Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, burbot, common carp, green sunfish, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, rock bass, shorthead redhorse, smallmouth bass, sunfish, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Gull Lake is located in Cass County, Minnesota.
When does Gull Lake thaw?
- Gull Lake typically has ice-out around Apr 21. Ice typically forms around Dec 1. The open water season is approximately 224 days.
Does Gull Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Gull Lake (clouds, ice, or an off-season gap). The most recent reading was low (15,704 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Gull Lake?
- Gull Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Government Point. Public access is listed as yes.
Explore Gull Lake across LakeGrade
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Moderate nutrients, good water quality
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Where this data comes from
95 measurements from 6 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 Water
MNPCA95 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (6)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
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