Wisconsin has thousands of lakes, but one of the biggest was built by people. Petenwell Lake, in rural central Wisconsin, sprawls across 23,173 acres, stretches 14 miles long and two miles wide, and holds the title of the state's largest artificial lake — and second-largest lake overall, behind only the 131,939-acre Lake Winnebago. It came into being in 1948, when the Petenwell Dam was built on the Wisconsin River to generate hydroelectric power and rein in a river that regularly flooded its banks. The dam was a genuine feat for its era: among the first in the United States constructed on sand, requiring deeply anchored walls to stay put.
Today the lake is less about engineering and more about water time. There's room for everyone — pontoons, sailboats and motorboats all share the water, whether you're towing tubers and water skis or drifting into the sunset. A dozen public boat launches dot the shoreline, and Barnum Bay Marina on the northeast side rents out pontoon boats. Anglers have serious options too: musky, walleye, northern pike, largemouth and smallmouth bass, panfish, sturgeon and catfish can all be caught, whether from a boat, a pier like Plaza Wisconsin on the northwest shore, or straight from the bank.
One caution worth heeding: Petenwell is shallow, and wind can turn it choppy fast. Locals advise against trying to cross the whole lake — stay within an easy swim of shore, especially if you're paddling a kayak among the sloughs, sandbanks and small islands.
Landlubbers are covered as well. Petenwell County Park, the second-largest county park in Wisconsin, has walking trails, while the Petenwell Bluff Trail on the south side packs a punch for its size — 0.8 miles and a 150-foot climb through pine forest to a rock outcrop with views over the lake and river. Bald eagles are sometimes spotted here, and you may see climbers scaling the bluff itself; it's a local rock climbing spot, ropes and harnesses included.
After a day on the water, the lakeside food scene leans heavily Wisconsin. The Lure Bar & Grill, next to Barnum Bay Marina, loads its menu with cheese — curds, poppers and a lineup of cheeseburgers — alongside non-dairy options like peel-and-eat shrimp and chicken wraps. At the lake's northern tip, Romano's Pizzeria draws praise for Chicago-style stuffed pizza, live music and sunset views.
Camping is easy on both shores. Petenwell County Park on the southeast side has multiple loops of campsites, an ATV/UTV campground connected to the Adams County trail system, a swimming area, boat launch, playground, game room and heated showers. Across the lake, Juneau County Wilderness Park is more rustic, with 127 campsites (most with electric hook-ups), showers, a small store and trails — reviewers suggest the wooded back sites if quiet matters more than lake views. For something with walls, Bay Rest Resort sits on the lakeshore, and Wisconsin Rapids has conventional lodging nearby.
If Wisconsin Dells an hour south is the state's high-energy theme park hub, Petenwell is its calmer cousin — a solid pick for anglers, boaters and campers who want a big lake without the crowds.