Gull Lake
Cass County, Minnesota10,010 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Gull Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- zebra mussel
- 80 ft max depth
- Public access
- Limited data
Gull Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. 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.
Minnesota DNR's Standard Survey on July 14, 2025 caught 5.67 walleye per gill net at Gull Lake. Length samples in the latest survey that recorded them ran 4–20 inches. DNR survey details →
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. The lake supports 22 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 3 public boat landings. 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. Methodology: how these readings are compared.
At about 10,000 acres, Gull Lake is large enough that where you stay decides which shore you see most of. It has 3 public boat landings, so a lakefront rental is not the only way to get a boat on the water. The median ice-out date is April 21, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Gull Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Gull Lake is good for
From access and monitoring records, not editorial picks.
- Clear water15 ft of visibility
- Boat launch3 documented ramps
- Fishing22 species recorded
- Ice seasonIce-out around Apr 21
- Deep water80 ft surveyed max depth
- Big water10,010 acres
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Gull Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Gull 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 Gull Lake
These are the measurements Minnesota PCA publishes for Gull Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 15 ft down. Phosphorus 13.5 µg/L. Chlorophyll-a 3 µg/L. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 15ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 13.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 3µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 40 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Gull Lake
Answers come straight from the public measurements and survey records on this page.
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 ↗
Minnesota DNR's Standard Survey on July 14, 2025 caught 5.67 walleye per gill net at Gull Lake. Length samples in the latest survey that recorded them ran 4–20 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Gull Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
37 surveys on file from MN DNR Fisheries. Most recent: 2025-09-23 (Targeted Survey).
37 surveys on file · most recent 2025-09-23 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Yellow Perch | 51.50 | 4–11 in 2025-07-14 | 0.11 lb |
| Walleye | 31.64 | 4–20 in 2025-09-23 | 1.24 lb |
| Largemouth Bass | 16.07 | 3–19 in 2025-07-14 | 0.89 lb |
| Bluegill | 14.44 | 2–8 in 2025-07-14 | 0.14 lb |
| Northern Pike | 11.66 | 20–38 in 2025-07-14 | 3.38 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.
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
Lake Details
Max depth
80 ft
Surface area
10,010 acres
Shoreline
46.1 mi
Littoral zone
28%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Recreation & Access
- North Long Lake (Northwest)Public
- Government PointPublic
- Gull Lake (East)Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays 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
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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Planning a trip? Cabins and lodging at Gull Lake → · more Minnesota lake trips
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Fish Species
Click a species to see every 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.
Ice season
Typical ice-out
Apr 21
Earliest Mar 17, 2024 · Latest May 18, 1950
Typical ice-in
Dec 1
Earliest Nov 14, 1959 · Latest Dec 22, 1998
Most recent ice-out
Apr 18
2025
138 observations · Minnesota PCA ice records
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
Designated uses not supporting: Fish consumption.
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.
Nearby Lakes in Cass County
Frequently asked questions about Gull Lake
Where is Gull Lake?
- Gull Lake is a lake in Cass County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Gull Lake?
- Gull Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. 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?
- Nutrient and algae readings are not a swimming clearance. Gull Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
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.
What did the DNR fisheries survey find at Gull Lake?
- Minnesota DNR's Standard Survey on July 14, 2025 caught 5.67 walleye per gill net at Gull Lake. Length samples in the latest survey that recorded them ran 4–20 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Gull Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
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 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include North Long Lake (Northwest), Government Point, Gull Lake (East). Public access is listed as yes.
Can I fish at Gull Lake?
- Gull Lake has 3 documented boat landings 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 Gull Lake across LakeQuality
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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)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate