Lake Koshkonong
Jefferson, Dane, Rock County, Wisconsin
About Lake Koshkonong
Lake Koshkonong is a serious fishing destination in Jefferson, Dane, Rock County, known for both its musky and walleye populations, covering 10,595 acres with a maximum depth of 7 feet. The lake has public boat landing access, making it easy to launch for a day on the water. Anglers primarily target Panfish. Note that invasive species (Curly-Leaf Pondweed, Zebra Mussel) have been documented here — clean your boat before leaving.
Bottom composition: 10% sand, 10% gravel, 0% rock, 80% muck
Type: lake · Hydrology: DRAINAGE
Lake Location
42.87240° N, 88.96120° W
WBIC 808700 · Wisconsin DNRFish Species
Full table →Fishing Tips
- ·Musky fishing is best in early morning and evening. Work weedlines and structural transitions with large bucktails or soft swimbaits.
- ·Wisconsin musky season typically opens the first Saturday in May. The fall bite (September–October) is peak for trophy fish.
- ·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 Lake Koshkonong? Local dining recommendations coming soon.
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Insider Tips
Local knowledge about Lake Koshkonong — 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
Curly-Leaf Pondweed, Zebra Mussel
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
Curly-Leaf Pondweed and Zebra Mussel have been documented in Lake Koshkonong. 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 Lake Koshkonong?
Lake Koshkonong is home to Catfish, Largemouth Bass, Musky, Northern Pike, Panfish (Common), Smallmouth Bass, and Walleye. Wisconsin fishing regulations apply — check current seasons and size limits before heading out.
Is there a public boat launch on Lake Koshkonong?
Yes — Lake Koshkonong has 4 boat landings providing watercraft access. Check for posted local ordinances at the landing before launching.
How big is Lake Koshkonong?
Lake Koshkonong has 10,595 acres in surface area, a maximum depth of 7 feet, a mean depth of 5 feet.
What is the bottom of Lake Koshkonong like?
The lake bottom is composed of 10% sand, 10% gravel, 0% rock, 80% muck. Sandy and gravel bottoms typically support good swimming and healthy fish habitat.
Are there invasive species in Lake Koshkonong?
Yes — Curly-Leaf Pondweed and Zebra Mussel have been documented in Lake Koshkonong. 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 Lake Koshkonong located?
Lake Koshkonong is located in Jefferson, Dane, Rock County, Wisconsin. GPS coordinates: 42.8724° N, 88.9612° W.
Are there vacation rentals on Lake Koshkonong?
Stay Northern is building the most complete rental directory for Jefferson, Dane, Rock County lakes. Check our Lake Koshkonong vacation rentals listing — if none are available yet, check back soon or browse nearby Jefferson, Dane, Rock County lake rentals.
Fishing Regulations
Current season regulations for Lake Koshkonong
| 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 And Smallmouth Bass | Open All Year | The minimum length limit is 14" and 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 | Open All Year | The minimum length limit is 26" and the daily bag limit is 2. | — |
| 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. | — |
| Trout | See specific regulations | https://dnr.wisconsin.gov/topic/fishing/trout/ . | — |
| Walleye, Sauger, And Hybrids | Open All Year | The minimum length limit is 18" 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
- 808700
- County
- Jefferson, Dane, Rock County
- Surface Area
- 10,595 acres
- Max Depth
- 7 ft
- Mean Depth
- 5 ft
- Bottom
- 10% sand, 10% gravel, 0% rock, 80% muck
- Lake Type
- lake
- Coordinates
- 42.8724, -88.9612
Boat Rentals Nearby
Pontoon
Listing soonFishing Boat + Motor
Listing soonKayak / Canoe
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Boat Landings (4)
Boat Landing 1
Boat Landing 2
Boat Landing 3
Boat Landing 4
Lake data sourced from the Wisconsin DNR. Last updated 3/24/2026.