WI · ranked by public data

The 9 Biggest Lakes in Jefferson County, Wisconsin

9 Jefferson County lakes cover at least 50 acres, out of 28 documented lakes in the county. Updated July 2026.

110,595 ac
10,595 acres
Jefferson County, WI
Lake Koshkonong
enhancedDepth mapDNR impairmentWater data
42.87, -88.9710,595 acres | 7 ft max4 public access pointsPanfish, Catfish
10,595 acres · 7 ft max depth · 4 public landings · DNR impairment listed
21,365 ac
1,365 acres
Jefferson County, WI
Rock Lake
enhancedDepth mapWater data
43.08, -88.931,365 acres | 60 ft max5 public access pointsLargemouth Bass, Panfish
1,365 acres · 60 ft max depth · 5 public landings
3420 ac
420 acres
Jefferson County, WI
Lake Ripley
enhancedDepth mapWater data
43.00, -88.99420 acres | 44 ft max2 public access pointsLargemouth Bass, Northern Pike
420 acres · 44 ft max depth · 2 public landings
4344 ac
344 acres
Jefferson County, WI
Red Cedar Lake
enhancedDepth mapWater data
42.98, -88.98344 acres | 6 ft max1 public access pointPanfish
344 acres · 6 ft max depth · 1 public landing
5136 ac
136 acres
Jefferson County, WI
Blue Spring Lake
enhancedDepth mapWater data
42.86, -88.60136 acres | 27 ft max1 public access pointPanfish, Largemouth Bass
136 acres · 27 ft max depth · 1 public landing
6108 ac
108 acres
Jefferson County, WI
Hope Lake
enhancedDepth mapWater data
43.03, -88.98108 acres | 24 ft max0 public access pointsLargemouth Bass, Northern Pike
108 acres · 24 ft max depth · No verified public access
7105 ac
105 acres
Jefferson County, WI
Spring Lake
enhancedDepth mapWater data
42.88, -88.57105 acres | 11 ft max1 public access pointSmallmouth Bass, Largemouth Bass
105 acres · 11 ft max depth · 1 public landing
884 ac
84 acres
Jefferson County, WI
Mud Lake
enhancedDepth mapDNR impairmentWater data
43.05, -88.9284 acres | 22 ft max0 public access pointsPanfish, Northern Pike
84 acres · 22 ft max depth · No verified public access · DNR impairment listed
972 ac
72 acres
Jefferson County, WI
Hahns Lake
enhancedDepth mapWater data
43.14, -88.7872 acres | 10 ft max0 public access pointsNorthern Pike, Panfish
72 acres · 10 ft max depth · No verified public access

Methodology

How this list is built

Ranked strictly by documented surface acres from DNR lake records.
Flowages and reservoirs count — they are lakes in the DNR's books, and some of the state's biggest water is impounded.
Lakes without documented acreage are excluded rather than estimated.
Lakes under 50 acres — or without documented acreage — are excluded from rankings.
Public access is shown for every lake but never affects the ranking.

FAQ

Jefferson County lake records

What is the biggest lake in Jefferson County?

Lake Koshkonong — Lake Koshkonong in Jefferson County is the biggest lake in Jefferson County, at 10,595 acres.

Biggest lakes statewide Deepest lakes in Jefferson County Clearest lakes in Jefferson County Lakes with the most public access in Jefferson County All Jefferson County lakes

Source data: Wisconsin DNR lake and monitoring records as aggregated by LakeList. Figures reflect the most recent documented values, not new surveys — verify access and rules before you go. Lake outlines are shoreline shapes from LakeList and the USGS National Hydrography Dataset; they illustrate a lake's form and are not depth or navigation charts.

WI · ranked by public data

The 9 Biggest Lakes in Jefferson County, Wisconsin

9 Jefferson County lakes cover at least 50 acres, out of 28 documented lakes in the county. Updated July 2026.

110,595 ac
10,595 acres
Jefferson County, WI
Lake Koshkonong
enhancedDepth mapDNR impairmentWater data
42.87, -88.9710,595 acres | 7 ft max4 public access pointsPanfish, Catfish
10,595 acres · 7 ft max depth · 4 public landings · DNR impairment listed
21,365 ac
1,365 acres
Jefferson County, WI
Rock Lake
enhancedDepth mapWater data
43.08, -88.931,365 acres | 60 ft max5 public access pointsLargemouth Bass, Panfish
1,365 acres · 60 ft max depth · 5 public landings
3420 ac
420 acres
Jefferson County, WI
Lake Ripley
enhancedDepth mapWater data
43.00, -88.99420 acres | 44 ft max2 public access pointsLargemouth Bass, Northern Pike
420 acres · 44 ft max depth · 2 public landings
4344 ac
344 acres
Jefferson County, WI
Red Cedar Lake
enhancedDepth mapWater data
42.98, -88.98344 acres | 6 ft max1 public access pointPanfish
344 acres · 6 ft max depth · 1 public landing
5136 ac
136 acres
Jefferson County, WI
Blue Spring Lake
enhancedDepth mapWater data
42.86, -88.60136 acres | 27 ft max1 public access pointPanfish, Largemouth Bass
136 acres · 27 ft max depth · 1 public landing
6108 ac
108 acres
Jefferson County, WI
Hope Lake
enhancedDepth mapWater data
43.03, -88.98108 acres | 24 ft max0 public access pointsLargemouth Bass, Northern Pike
108 acres · 24 ft max depth · No verified public access
7105 ac
105 acres
Jefferson County, WI
Spring Lake
enhancedDepth mapWater data
42.88, -88.57105 acres | 11 ft max1 public access pointSmallmouth Bass, Largemouth Bass
105 acres · 11 ft max depth · 1 public landing
884 ac
84 acres
Jefferson County, WI
Mud Lake
enhancedDepth mapDNR impairmentWater data
43.05, -88.9284 acres | 22 ft max0 public access pointsPanfish, Northern Pike
84 acres · 22 ft max depth · No verified public access · DNR impairment listed
972 ac
72 acres
Jefferson County, WI
Hahns Lake
enhancedDepth mapWater data
43.14, -88.7872 acres | 10 ft max0 public access pointsNorthern Pike, Panfish
72 acres · 10 ft max depth · No verified public access

Methodology

How this list is built

Ranked strictly by documented surface acres from DNR lake records.
Flowages and reservoirs count — they are lakes in the DNR's books, and some of the state's biggest water is impounded.
Lakes without documented acreage are excluded rather than estimated.
Lakes under 50 acres — or without documented acreage — are excluded from rankings.
Public access is shown for every lake but never affects the ranking.

FAQ

Jefferson County lake records

What is the biggest lake in Jefferson County?

Lake Koshkonong — Lake Koshkonong in Jefferson County is the biggest lake in Jefferson County, at 10,595 acres.

Biggest lakes statewide Deepest lakes in Jefferson County Clearest lakes in Jefferson County Lakes with the most public access in Jefferson County All Jefferson County lakes

The 9 Biggest Lakes in Jefferson County, Wisconsin

Lake Koshkonong

Rock Lake

Lake Ripley

Red Cedar Lake

Blue Spring Lake

Hope Lake

Spring Lake

Mud Lake

Hahns Lake

How this list is built

Jefferson County lake records

What is the biggest lake in Jefferson County?

The 9 Biggest Lakes in Jefferson County, Wisconsin

Lake Koshkonong

Rock Lake

Lake Ripley

Red Cedar Lake

Blue Spring Lake

Hope Lake

Spring Lake

Mud Lake

Hahns Lake

How this list is built

Jefferson County lake records

What is the biggest lake in Jefferson County?