Lake Koshkonong · Fort Atkinson, Wisconsin

Your private sand beach on Southern Wisconsin's largest lake

$1,500,000 Offered for sale by owner · Buyer’s agents welcome
4 bedrooms
4 full baths
4,100 sq ft, all above grade
130′ sand beach frontage
1.28 acres

The rarest shoreline on the lake

Nearly every lakefront lot on Lake Koshkonong meets the water with a boulders-only shoreline or a bluff with several flights of stairs. This one doesn’t. Here, a level lawn rolls straight into 130 feet of private sand beach - a walk-in swimming beach with a sand bottom that stays gentle past the end of the pier.

Kids wade in without a ladder. Grandparents walk to the pontoon without a single stair. The beach chairs sit on pristine beach. Swim, boat, jet ski, fish, ski, and tube by day. Relax in the hot tub or with a camp fire by night.

130 feet of walk-in sand beach

Walk-in sand beach

Easy access, kid friendly, and ready for dawn-to-dusk lake activities

Custom brick, 4,100 sq ft

4 bedrooms, 4 full baths, hot tub, granite & stainless kitchen, heated 2-car garage.

Turnkey lake fun

Pier and boat lift included. Pontoon boat, jet skis, and the water-toy fleet available.

3D tour & floor plans

Click any point on the plan to stand in that room.

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Floor plan with dimensions — main level
Floor plan with dimensions — main level
Floor plan with dimensions — upper level
Floor plan with dimensions — upper level

Download the full floor plan with dimensions (PDF)

Property details

The residence

Living area 4,100 sq ft — all above grade
Bedrooms 4
Bathrooms 4 full
Built 2001, custom brick construction
Kitchen Granite counters, large stainless range & oven, stainless appliances
Screened porch Hot tub, conveys with the sale
Attached garage 2-car, heated
Driveway Concrete

The waterfront

Frontage 130 ft on Lake Koshkonong
Shoreline 100% private sand beach, sand bottom
Included Pier & boat lift
Water at pier ~3 ft - ideal for pontoon boat & jet skis
Exposure East — sunrise over the water, shaded deck evenings

Land & outbuildings

Lot 1.28 acres across two parcels, conveying together
Detached garage 25 × 40 ft (1,000 sq ft) - shop, storage, toys
Irrigation Lawn irrigation system

Taxes & district

Property taxes (2025) $10,146
Schools School District of Fort Atkinson
County Jefferson County — Town of Sumner
Lake district Rock-Koshkonong Lake District

Southern Wisconsin’s largest lake

Ten thousand acres of big, open water forty minutes from Madison’s doorstep. Lake Koshkonong is one of Wisconsin’s largest inland lakes - a broad, warm lake fed by the Rock River. It's famous for pontoon afternoons, sandbar summers, and some of the best fishing in southern Wisconsin.

Shallow and sun-warmed, Lake Koshkonong turns swimmable weeks before the deep glacial lakes do — and its sand-bottom shallows are exactly what pontoon-and-beach summers are made of. Anglers work the same water for walleye, crappie, white bass, and channel cats. Hunters know the marshes as a legendary waterfowl flyway. Winter brings ice fishing villages and snowmobile trails straight off the shore.

Outline of Lake Koshkonong, roughly four miles of open water across
10,460 acres of water
Top 10 largest inland lakes in Wisconsin
~4 mi of open water to the far shore
12 mo of lake life: boats to ice shanties

Buyer’s agents welcome

This home is offered for sale by owner. The sellers welcome representation and are offering buyer-agent compensation of 2.5%, confirmed in a written compensation agreement with each offer.

Get in touch about a showing

Schedule a private showing

Private showings by appointment. We ask for a mortgage pre-approval letter or proof of funds before confirming a showing.

Buyer’s agents: the sellers are offering compensation of 2.5%, confirmed in a written compensation agreement with each offer.

Call Schedule a showing