Anglers can find plenty of keepers on Lake Koshkonong
Fort Atkinson-If you're looking for some good
walleye action, try Lake Koshkonong.
"The reality is that walleye fishing in southern Wisconsin can
be tough," said Gary Wroblewski, a guide who has fished Koshkonong
for ten years. "This is a lake where you can catch walleyes. You're
going to catch other fish, too. You never know what's at the end of
your line. But every once in a while, you'll catch a nice
Lake Koshkonong is a 10,460-acre lake in southwestern Jefferson
County, with a maximum depth of just seven feet.
According to Don Bush, regional fisheries supervisor with the
Department of Natural Resources at Janesville, Koshkonong was
transformed from a deep-water marsh to a big, shallow lake by the
Indianford dam on the Rock River, which was completed in 1917.
"Walleye is probably the most highly sought-after fish," Bush
The state stocks walleyes in Koshkonong to supplement a natural
population. "We estimate that about 25% of the walleye fishery is
stocked and 75% is natural," Bush said.
Koshkonong has had a carp problem for decades, and stocking of
game fish is tied to carp removal. Private contractors, supervised
by the DNR, take an average of about two million pounds of carp out
of the lake each year.
Carp get into the lake from the Rock River, which flows through
Koshkonong. Game fish and panfish are stocked to prey on carp and
occupy the habitat they would otherwise use.
"The lake, itself, is prime habitat for carp - big and shallow
with a muddy bottom and abundant lake fly larvae," Bush said. "That
food is also the bread and butter for walleyes, catfish, panfish
and white bass."
Typically, the lake gets about three million walleye fry a year
but, this year, 500,000 one-inch walleye fingerlings were stocked.
"We've had enormous success with fry stocking," Bush said. "We're
trying to get a cost-benefit analysis of the fingerlings."
The DNR has re-established a sauger population and is trying to
do the same with yellow perch and flathead catfish. The state also
stocks between 500,000 and 2 million northern pike fry a year to
supplement a natural population, plus about 2,500 muskies.
In addition, the lake has naturally reproducing populations of
white bass, largemouth bass, some smallmouth bass, channel catfish,
bullheads, black crappies and bluegills.
Watersport Boat Rental, 723 E. Ellendale Road, Town of Newville,
has two fishing boats with outboards for $65 a half-day or $85 a
day, plus tax and gas. A $200 credit card security deposit is
Major boat landings are located off Charlie Bluff Road on the
southwest side of the lake, Keuhn and Carcajou Roads on the north,
North Shore Road on the northeast and Vinnie Haha Road on the
"If people have large boats, they're probably better off
launching in the river," Bush advised. The DNR has free launches on
the Rock River, off Groeler Road under the Highway 26 bypass, east
of the lake; and about a mile downstream from I-90 in Newville,
southwest of the lake.
Wroblewski, of Eagle, Larry Awe, of Wauwatosa, and I paid $4 to
launch at the Riverfront tavern on Blackhawk Island - one of
several additional private landings - and motored out to mid-lake
on a recent cloudy evening with shifting winds and weather fronts
"Koshkonong is almost always better when it's windy," Wroblewski
said. "I think wind increases the feeding activity."
Don't look for any sharp drop-offs, rock bars or other major
"The lake is pretty much a big flat, so you look for changes
from muck to sand bottom and subtle differences in depth,"
Wroblewski explained. "A foot or two change in depth can make the
We set up four trolling rods with line-counter reels and
eight-pound monofilament line, and tied on three-inch crank baits,
which we set 10 to 12 feet behind planer boards dragged 25 to 35
yards behind the boat.
We trolled at about 2 mph and, for the next five hours, had
steady action reeling in a mixed bag of fish. We caught about 25
white bass, 2 northerns, a bullhead, 2 saugers and about a dozen
walleyes, up to almost 19 inches long. We released everything but a
couple of the walleyes, which we kept to eat.
"You'll likely catch more undersized walleyes than 'keepers,' "
Bush said. "But Koshkonong can produce trophies. I've heard of
several walleyes in the 27-inch range taken this year."
Call Bob Riepenhoff at (414) 224-2313 or e-mail him at