What Lake Onalaska Offers

Lake Onalaska is a 6,000-acre backwater impoundment on the Upper Mississippi River between the towns of Onalaska and La Crosse, Wisconsin. It holds walleye, largemouth bass, smallmouth bass, channel catfish, flathead catfish, and panfish — a mix that draws both tournament anglers and people fishing from shore or boat for a relaxed day. The lake is shallow, averaging 5 to 8 feet deep, with extensive weed beds and woody cover that hold fish year-round but change how and where you fish across the seasons.

Access is straightforward: public boat launches sit at Onalaska City Park on the north shore and at Holmen Bottoms on the south. Both have parking, and neither charges a launch fee. The lake is protected from heavy wind by surrounding bluffs, making it fishable on days when larger waters are rough. Because it is part of the Mississippi River system, you do not need a separate lake permit — your Wisconsin fishing license covers it.

Key Takeaways

  • Walleye fishing peaks in spring (April through May) and fall (September through October), with live shiners or jigs worked along deeper edges and near the dam.
  • Largemouth bass are abundant in shallow weed beds and around fallen timber year-round, with topwater lures productive in early morning and evening.
  • Channel and flathead catfish bite throughout summer and fall, especially at night, using chicken liver, cut bait, or live bluegill.
  • The lake is shallow and weedy, so a depth finder and weed-tolerant lures (spinnerbaits, soft plastics) are more useful than deep-water gear.
  • Public boat launches at Onalaska City Park and Holmen Bottoms are free and open year-round, though winter access depends on ice conditions.

Walleye Fishing in Spring and Fall

Walleye are the most sought species on Lake Onalaska, and the best windows are April through May and September through October. In spring, fish move shallow to spawn and feed heavily before and after the event. Work the deeper edges of weed beds — typically 8 to 12 feet — with live shiners or small jigs tipped with minnow. Early morning and dusk are most productive, but walleye will bite throughout the day if cloud cover is heavy.

The dam area at the south end of the lake concentrates walleye in both seasons because current and structure funnel baitfish. Fish the riprap and deeper water immediately below the dam with a jig-and-minnow or a live shiner on a slip sinker. Fall fishing is often better than spring because the water is clearer and fish are feeding hard before winter. By November, walleye move deeper and bite less reliably, though night fishing with live bait can still produce.

Summer walleye fishing is slow because fish move to the deepest holes — rare on this shallow lake — and become less active in warm water. If you fish June through August, focus on early morning before the sun is high, and fish the deepest holes you can find with your depth finder, usually near the dam or in the main channel.

Largemouth Bass and Shallow-Water Cover

Largemouth bass thrive in Lake Onalaska's weed beds and woody structure, and they are catchable every month. Spring (April and May) and fall (September and October) are peak seasons, but summer and even winter produce if you fish the right cover. The lake's shallow depth means bass rarely move far from weeds or timber — they are ambush predators in a shallow system, so they stay where prey is trapped.

Fish topwater lures (poppers, walk-the-dog baits) in early morning and evening around weed edges and fallen trees. As the sun rises, switch to soft plastics — 4-inch worms or creature baits — rigged Texas-style and worked slowly through the thickest cover. Spinnerbaits are excellent year-round because they move through weeds without snagging as often as other lures. If you are new to the lake, start at the north end near Onalaska City Park, where weed beds are dense and easy to locate.

Smallmouth bass are also present but less abundant than largemouths. They prefer harder bottom and deeper water, so fish rocky areas and the dam structure with jigs or drop-shot rigs if you want to target them specifically.

Catfish: Channel and Flathead

Channel catfish and flathead catfish both inhabit Lake Onalaska and offer a different kind of fishing — typically at night, with heavy tackle and patience. Channel catfish bite year-round but are most active May through September. Use chicken liver, cut shad, or stink bait on a three-way rig or simple slip sinker, and fish the deeper holes and channel edges. You can catch them from shore at the boat launches or from a boat anchored in 10 to 15 feet of water.

Flathead catfish are larger and more aggressive than channels. They hunt live baitfish, so use live bluegill, shiners, or small sunfish on a heavy rod and reel. Fish at night, especially in summer and early fall, and expect powerful runs. Flatheads are less common than channels but growing in number, and a 40-pound flathead is possible. Both species are good eating if you want to keep them.

Panfish and Year-Round Fishing

Bluegill, crappie, and pumpkinseed sunfish are abundant in the shallows and weed beds. Spring and early summer are best, when fish move shallow to spawn. Use a light rod, small jigs (1/32 to 1/16 ounce), or live crickets and waxworms, and fish the weed edges in 2 to 6 feet of water. A panfish can keep you busy all morning, and they are excellent for children or anyone wanting consistent action without the need for specialized technique.

Winter panfish fishing is possible through the ice, though the lake does not always freeze solid enough for safe ice fishing — check local conditions before you go. When ice is present, drill holes in 6 to 10 feet of water near weed beds and use small jigs or live minnows.

Seasons, Regulations, and What to Bring

Wisconsin's fishing season runs year-round for most species on Lake Onalaska. Walleye have a specific season (generally January 1 through March 31 and May 1 through December 31, with a closed period in April for spawning), so check the current Wisconsin Department of Natural Resources (WDNR) fishing guide before you go. Bass season is open year-round. Catfish have no closed season. Daily bag limits vary by species — walleye is typically 5 per day, largemouth bass is 5 per day, and catfish have no limit — but confirm the current rules on the WDNR website.

Bring a depth finder if you have one; the lake's shallow, weedy character makes it hard to find structure by sight alone. A weed-tolerant rod and reel (medium-power, 6 to 7 feet) works for most species. Polarized sunglasses help you spot fish in the shallows. Life jackets are required by law, and the lake can be windy in afternoon, so wear one even if you are a strong swimmer.

The lake is open to public fishing year-round, but winter access depends on ice conditions. Spring and fall are the most reliable seasons for consistent fishing and comfortable weather. Summer is warm but slower for walleye; it is better for bass and catfish. Avoid the opening weekend of walleye season (early May) if you prefer solitude — the lake draws crowds then.

Getting There and Where to Stay

Lake Onalaska sits between the towns of Onalaska and La Crosse, about 140 miles southeast of Madison. From Madison, take I-90 east toward La Crosse; the drive is roughly 2.5 hours. Onalaska City Park is on the north shore (take Exit 3 from I-90 and follow signs); Holmen Bottoms is on the south shore near the town of Holmen. Both launches have parking and are open dawn to dusk year-round.

La Crosse, 10 miles south, has hotels, restaurants, and a full range of services. Onalaska itself is smaller but has a few lodging options and a grocery store. If you want to fish early morning, staying in Onalaska or La Crosse the night before saves driving time. The Upper Mississippi River National Wildlife and Fish Refuge surrounds much of the lake and offers scenic walking trails if you want to explore between fishing sessions.

Frequently Asked Questions

What is the best time of year to fish Lake Onalaska?

Spring (April and May) and fall (September and October) are best overall because walleye bite well, bass are active, and weather is mild. Summer is slower for walleye but good for bass and catfish. Winter is possible but depends on ice conditions and is less predictable.

Do I need a boat to fish Lake Onalaska?

No. Both public launches have shore-fishing access, and Onalaska City Park has a shoreline where you can fish from land. A boat gives you more water to cover and access to deeper structure, but panfish and bass are catchable from shore in the weed beds near the launches.

What size fish can I expect to catch?

Walleye average 1 to 3 pounds, with fish over 5 pounds possible in spring and fall. Largemouth bass average 1 to 2 pounds, with occasional fish over 4 pounds. Channel catfish run 2 to 8 pounds; flatheads are larger, often 15 to 40 pounds. Panfish are typically 4 to 8 inches.

Is Lake Onalaska safe to fish in winter?

The lake does not always freeze solid, and ice conditions vary year to year. Check with the Onalaska Parks Department or a local bait shop before attempting ice fishing. If ice is present and deemed safe by local authorities, winter panfish fishing is possible.

Can I keep fish I catch on Lake Onalaska?

Yes. Walleye, bass, catfish, and panfish are all legal to keep within daily bag limits. Walleye and catfish are good eating. Check the WDNR fishing guide for current bag limits before you fish.