Cosgrove Lake
Florence County, Wisconsin
About Cosgrove Lake
Cosgrove Lake earns its reputation as one of Florence County's premier walleye fisheries, a intimate 76-acre lake reaching 26 feet at its deepest. Access is limited, which keeps boat traffic low — a plus for solitude seekers. The fishery includes Northern Pike, Panfish, Smallmouth Bass, and Walleye. Note that invasive species (Purple Loosestrife) have been documented here — clean your boat before leaving.
Bottom composition: 75% sand, 5% gravel, 0% rock, 20% muck
Type: lake · Hydrology: SEEPAGE
Lake Location
45.89390° N, 88.16530° W
WBIC 585100 · Wisconsin DNRFish Species
Full table →Fishing Tips
- ·Walleye feed most actively at dawn and dusk. Jig along deep structural breaks or troll crankbaits along weedlines at 6–8 ft depth.
- ·Night fishing under a full moon can produce excellent walleye results from late June through August.
- ·Northern pike are ambush predators — target weed edges, fallen timber, and points with large spoons or swimbaits.
- ·Spring pike fishing (ice-out through June) can be outstanding as they move into shallow, warming bays to spawn.
- ·Largemouth bass relate to shallow structure. Work topwater lures at dawn in summer, then switch to soft plastics rigged weedless around lily pads and fallen wood.
- ·Bluegill and crappie stack up in 8–15 ft of water near weedlines. Small jigs tipped with a waxworm are hard to beat.
- ·Panfish are often excellent for kids and beginners — look for them around any dock or submerged brush piles.
Local's Guide
Fishing
Species-specific tips above. Wisconsin fishing license required for ages 16+. See current season regulations below.
View fishing regulations ↓Swimming
Sandy bottom sections make for good swimming. No lifeguard on duty — swim at your own risk.
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Nearby Dining
Looking for supper clubs and bait shops near Cosgrove Lake? Local dining recommendations coming soon.
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Insider Tips
Local knowledge about Cosgrove Lake — best times to visit, quiet spots, and what the regulars know. Contributed tips coming soon.
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Lake Conditions
Water Clarity
—
No data
Trophic Status
—
No data
Invasive Weeds
Present
Purple Loosestrife
Seasonal Notes
Coming soon
Ice-out dates, peak fishing windows
Condition data sourced from Wisconsin DNR surveys. Real-time weed and clarity reports coming soon.
Invasive Species Present
Purple Loosestrife has been documented in Cosgrove Lake. Clean, drain, and dry all watercraft and equipment before leaving.
Report sightings to the Wisconsin DNR invasive species hotline.Frequently Asked Questions
What fish can you catch in Cosgrove Lake?
Cosgrove Lake is home to Northern Pike, Panfish, Smallmouth Bass, and Walleye. Wisconsin fishing regulations apply — check current seasons and size limits before heading out.
Can you boat on Cosgrove Lake?
Cosgrove Lake does not currently have a public boat landing listed in the Wisconsin DNR database. Shore fishing or kayak/canoe access may still be available — check local access points.
How big is Cosgrove Lake?
Cosgrove Lake has 76 acres in surface area, a maximum depth of 26 feet, a mean depth of 6 feet.
What is the bottom of Cosgrove Lake like?
The lake bottom is composed of 75% sand, 5% gravel, 0% rock, 20% muck. Sandy and gravel bottoms typically support good swimming and healthy fish habitat.
Are there invasive species in Cosgrove Lake?
Yes — Purple Loosestrife has been documented in Cosgrove Lake. Please clean, drain, and dry your watercraft and all equipment before leaving any Wisconsin water body to prevent the spread of invasive species.
Where is Cosgrove Lake located?
Cosgrove Lake is located in Florence County, Wisconsin. GPS coordinates: 45.8939° N, 88.1653° W.
Are there vacation rentals on Cosgrove Lake?
Stay Northern is building the most complete rental directory for Florence County lakes. Check our Cosgrove Lake vacation rentals listing — if none are available yet, check back soon or browse nearby Florence County lake rentals.
Fishing Regulations
Current season regulations for Cosgrove Lake
| Species | Season | Min. Length | Daily Bag |
|---|---|---|---|
| Bullheads | Open All Year | No minimum length limit and the daily bag limit is unlimited. | — |
| Catfish | Open All Year | No minimum length limit and the daily bag limit is 10. | — |
| Cisco And Whitefish | Open All Year | No minimum length limit and the daily bag limit is 10. | — |
| Lake Sturgeon | Closed | No fishing allowed. | — |
| Largemouth Bass | May 2, 2026 to June 19, 2026 | No minimum length, but largemouth bass from 14" to 18" may not be kept, and only 1 fish over 18 is allowed. The daily bag limit is 5. | — |
| Largemouth Bass And Smallmouth Bass | June 20, 2026 to March 7, 2027 | No minimum length, but largemouth bass and smallmouth bass from 14" to 18" may not be kept, and only 1 fish over 18 is allowed. The daily bag limit is 5. | — |
| Muskellunge And Hybrids | May 2, 2026 to December 31, 2026 on open water | The minimum length limit is 40" and the daily bag limit is 1. | — |
| Northern Pike | May 2, 2026 to March 7, 2027 | No minimum length limit and the daily bag limit is 5. | — |
| Paddlefish | Closed | No fishing allowed. | — |
| Panfish | Open All Year | No minimum length limit and the daily bag limit is 25. | — |
| Rock, Yellow, And White Bass | Open All Year | No minimum length limit and the daily bag limit is unlimited. | — |
| Rough Fish | Open All Year | No minimum length limit and the daily bag limit is unlimited. | — |
| Round Goby | Open All Year | The daily bag limit is 0, one may be killed and possessed for transport to a WDNR Office. | — |
| Ruffe | Open All Year | The daily bag limit is 0, one may be killed and possessed for transport to a WDNR Office. | — |
| Shovelnose Sturgeon | Closed | No fishing allowed. | — |
| Smallmouth Bass | May 2, 2026 to June 19, 2026 | Fish may not be harvested (catch and release only). | — |
| Trout | See specific regulations | https://dnr.wisconsin.gov/topic/fishing/trout/ . | — |
| Walleye, Sauger, And Hybrids | May 2, 2026 to March 7, 2027 | The minimum length limit is 15" and the daily bag limit is 3. | — |
| White Perch | Open All Year | The daily bag limit is 0, one may be killed and possessed for transport to a WDNR Office. | — |
Regulations sourced from Wisconsin DNR fisheries data. Always verify current regulations before fishing.
Lake Details
- WBIC
- 585100
- County
- Florence County
- Surface Area
- 76 acres
- Max Depth
- 26 ft
- Mean Depth
- 6 ft
- Bottom
- 75% sand, 5% gravel, 0% rock, 20% muck
- Lake Type
- lake
- Coordinates
- 45.8939, -88.1653
Boat Rentals Nearby
Pontoon
Listing soonFishing Boat + Motor
Listing soonKayak / Canoe
Listing soonKnow a local boat rental operator near Cosgrove Lake? Let us know.
Lake data sourced from the Wisconsin DNR. Last updated 3/24/2026.