Sullivan Lake
Morrison County, Minnesota1,103 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Sullivan Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- 57 ft max depth
- Public access
Sullivan Lake in Morrison County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.8 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 5 µg/L. Maximum depth: 57 ft. Surface area: 1103.4 acres.
Minnesota DNR's Targeted Survey on June 23, 2025 caught 0.46 largemouth bass per hour of electrofishing at Sullivan Lake. Length samples in the latest survey that recorded them ran 5–19 inches. DNR survey details →
Free interactive depth-contour map of Sullivan Lake, reaching a maximum surveyed depth of 50 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Sullivan Lake is a 1,103-acre mesotrophic lake in Morrison County, Minnesota with a maximum depth of 57 feet (18-foot average). Overall water quality is declining over recent sampling years. The lake supports 18 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings. Compared to the 7 other monitored lakes in Morrison County, Sullivan Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-24. Methodology: how these readings are compared.
Sullivan Lake covers about 1,100 acres in Morrison County. It has 2 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 19, which is when the open-water season begins. Vrbo is where to look for cabins and lake homes around Sullivan Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Sullivan Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10.8 ft of visibility
- Boat launch2 documented ramps
- Fishing18 species recorded
- Ice seasonIce-out around Apr 19
- Deep water57 ft surveyed max depth
- Big water1,103 acres
Swimming conditions
Readings onlyLow algae
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. Sullivan Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Sullivan 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 Sullivan Lake
These are the measurements Minnesota PCA publishes for Sullivan 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 10.8 ft. Phosphorus 14 µg/L. Chlorophyll-a 5 µg/L. TSI 44.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 14µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 5µg/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. | 44 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Sullivan Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Sullivan Lake typically sits around 61°F at the surface in September. Summer average is about 65°F. Usually warmest in Aug (about 67°F) and coldest in May (about 56°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (56°F) to its warmest (67°F).
Typical surface water temperature by month, from 181 field readings (2016–2025) via the EPA Water Quality Portal. See the full Sullivan Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on June 23, 2025 caught 0.46 largemouth bass per hour of electrofishing at Sullivan Lake. Length samples in the latest survey that recorded them ran 5–19 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Sullivan Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
30 surveys on file from MN DNR Fisheries. Most recent: 2025-06-23 (Targeted Survey).
30 surveys on file · most recent 2025-06-23 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 15.74 | 2–9 in 2025-05-15 | 0.22 lb |
| Walleye | 10.64 | 4–28 in 2025-05-15 | 1.49 lb |
| Largemouth Bass | 8.88 | 5–19 in 2025-05-15 | 1.51 lb |
| Bluntnose Minnow | 8.14 | ||
| Yellow Perch | 6.80 | 5–7 in 2025-05-15 | 0.15 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
Walleye
Largemouth Bass
Yellow Perch
From the 2025-06-23 survey
A targeted survey of nearshore fish species in Sullivan Lake, was conducted on June 23rd-24th, 2025, by Area Fisheries staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack electrofishing was…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Sullivan Lake. 5 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — SullivanFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Sullivan (0241)Aquatic Plant Report · MN DNR LakeFinder
- —Aquatic Plant Report — Sullivan (1926)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — SullivanFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — SullivanPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
57 ft
Average depth
17.6 ft
Surface area
1,103 acres
Shoreline
7.7 mi
Littoral zone
51%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
43 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,243 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Sullivan Lake (West)Public
- Sullivan 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 Sullivan Lake
Compare lakeside cabins, hotels, and vacation rentals near Sullivan Lake in Morrison 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 Sullivan 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 Sullivan 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 Sullivan Lake
Water Quality Trend: Worsening
Based on 4 years of monitoring (2020–2024).
Water clarity
Worsening4 years
Phosphorus
Worsening+0.66 µg/L/yr4 years
Chlorophyll-a
Worsening+0.65 µg/L/yr4 years
Ice season
Typical ice-out
Apr 19
Earliest Mar 19, 2012 · Latest Apr 29, 1996
Typical ice-in
Nov 30
Earliest Nov 27, 2023 · Latest Dec 20, 2001
Most recent ice-out
Apr 29
2023
33 observations · Minnesota PCA ice records
EPA Impairment Status
Sullivan 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 MN49-0016-00 · Official waterbody report
Nearby Lakes in Morrison County
Frequently asked questions about Sullivan Lake
Where is Sullivan Lake?
- Sullivan Lake is a lake in Morrison County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Sullivan Lake?
- Sullivan Lake in Morrison County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10.8 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 5 µg/L. Maximum depth: 57 ft. Surface area: 1103.4 acres.
Is Sullivan Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Sullivan Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Sullivan Lake?
- Sullivan Lake typically sits around 61°F at the surface in September, from 181 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
How deep is Sullivan Lake?
- Sullivan Lake has a maximum depth of 57 feet and an average depth of 17.6 feet. The lake covers 1103.4 acres.
What fish are in Sullivan Lake?
- Fish species found in Sullivan Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Sullivan Lake is located in Morrison County, Minnesota.
What did the DNR fisheries survey find at Sullivan Lake?
- Minnesota DNR's Targeted Survey on June 23, 2025 caught 0.46 largemouth bass per hour of electrofishing at Sullivan Lake. Length samples in the latest survey that recorded them ran 5–19 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Sullivan Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Sullivan Lake thaw?
- Sullivan Lake typically has ice-out around Apr 19. Ice typically forms around Nov 30. The open water season is approximately 225 days.
Are there boat ramps on Sullivan Lake?
- Sullivan Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Sullivan Lake (West), Sullivan Lake (East). Public access is listed as yes.
Can I fish at Sullivan Lake?
- Sullivan Lake has 2 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 Sullivan Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Morrison County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Sullivan Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Compare Sullivan Lake With Nearby Lakes
Where this data comes from
57 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA57 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
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