Spring migration is one of the great underappreciated spectacles in northern Wisconsin — and Oconto County is quietly one of the best places in the state to watch it unfold. The county sits along a major migratory flyway on the western shore of Green Bay, with a mix of wetlands, river corridors, open water, and national forest that draws an extraordinary range of species from late March through May. Whether you’ve been birding for decades or you’ve just started noticing how many different birds are suddenly showing up, this is a great time to pay attention.
Here’s what to watch for, and where to find it — starting closest to Green Bay and working north into the Nicolet.
A Note on Timing
Spring migration in Wisconsin generally kicks off in earnest in late March and ramps up through April and May. Geese, ducks, sandhill cranes, robins, red-winged blackbirds, and bluebirds tend to be among the earliest arrivals. Warblers and songbirds follow as temperatures warm and insects become more abundant, with peak migration typically running mid-April through mid-May.
Abrams Waterfowl Project
Approximately 20 miles from Green Bay · About 25 minutes
A 152-acre site with excellent access for watching ducks, geese, ruffed grouse, pheasants, and wild turkeys. One of the closest quality birding spots to Green Bay and a great first stop if you’re heading north.
Primary access via US-41 northbound — the improved parking lot is just past the US-41/US-141 split.
Pensaukee Unit — Green Bay West Shores State Wildlife Area
Approximately 27 miles from Green Bay · About 35 minutes
A 308-acre site one mile south of Pensaukee on Cty S. This is a strong spot for common mergansers, common goldeneyes, American snowy egrets, yellow rails, and peregrine falcons — particularly during spring migration. Yellow rails are notoriously secretive, but spring is your best shot at finding one.
The Oconto Harbor & Breakwater
Approximately 32 miles from Green Bay · About 35–40 minutes
If you only go one place this spring, make it the Oconto Harbor. It’s an eBird-designated birding hotspot and one of the most productive spots in northeast Wisconsin — the combination of open water, the breakwater structure, and proximity to the marsh creates a concentrated viewing area for a remarkable variety of species.
In spring, scan the water for diving ducks moving through on their way north — scaup, goldeneyes, mergansers, and buffleheads are all possible. Green Bay is one of the largest freshwater estuaries in the world and is critical habitat for migrating waterfowl, particularly diving ducks. The harbor puts you right in the middle of that action.
While you’re there, look south from the marina — there’s a bald eagle nest visible from Oconto City Breakwater Park. Eagles are year-round residents along the Oconto River corridor, and spring is a particularly active time as nesting activity picks up. Oconto County is part of the Bald Eagle Nest Watch program, which monitors nests across Brown, Oconto, and Shawano counties.
One more bonus: the Oconto Harbor is one of Wisconsin’s best-known snowy owl spots — though this is primarily a winter phenomenon. Snowy owls typically arrive in mid-November and depart by the end of March, so if you’re reading this in early spring, there’s a small window to catch a lingering bird on the breakwater before they head back north. Worth a look.
Oconto Marsh & Rush Point — Green Bay West Shores State Wildlife Area
Approximately 35 miles from Green Bay · About 40 minutes
Just north of the city of Oconto, the Oconto Marsh and Rush Point State Wildlife Area covers 800 acres of prime wetland habitat along Green Bay. This is one of the county’s signature birding spots and deserves its own morning.
White pelicans, Caspian and common terns, long-tailed ducks, red-throated loons, and scoters have all been recorded here. Spring migration brings waterfowl through in big numbers, and the marsh edges are good for herons, egrets, and shorebirds as the season progresses.
Access: From downtown Oconto, follow Cty Y east, turn right on Harbor Rd and follow 0.25 miles to the breakwater, then follow Cty Y north to reach the marsh and Rush Point properties.
Machickanee Unit (Oconto Falls Area)
Approximately 38 miles from Green Bay · About 45 minutes
A 3,100-acre unit in the Oconto River Valley. Red-shouldered hawks, Blackburnian warblers, Swainson’s thrushes, and ruby-crowned kinglets have all been recorded here. The Oconto River corridor as a whole is excellent for migrating warblers and songbirds in May — this is the stretch that draws serious birders from outside the county.
Directions: North of the river, drive east on Cty I (Stiles Road); south of the river, use Konitzer Rd and Timberline Rd.
Peshtigo Brook State Wildlife Area (near Suring)
Approximately 50 miles from Green Bay · About 1 hour
At 2,200 acres, this is one of the larger natural areas in the southern part of the county. Look here for ruffed grouse, barred owls, common nighthawks, merlins, loggerhead shrikes, and warbling vireos. Spring is a good time to listen for owls at dusk and dawn before the leaves fill in and make audio harder to isolate.
Directions: From Hwy 141 north of Pound, travel west 10 miles on Hwy 64 to the property, which is south of the highway.
North County: The Nicolet National Forest
For those looking for more adventure, the Nicolet National Forest offers a completely different birding experience — wilder, quieter, and worth the drive. The spots below make a natural day trip, and the Hagar Mountain / Cathedral Pines / Snow Falls Creek trio in particular pairs beautifully as a single north-county morning.
Hwy 64 Wetlands (near Mountain)
Approximately 69 miles from Green Bay · About 1 hour 25 minutes
Open all year, the Hwy 64 Wetlands near Mountain are known for short-eared owls, dickcissels, Brewer’s blackbirds, American pipits, and Lapland longspurs — birds more typically associated with open tundra and grassland that move through during migration. A very different bird list than the shore and forest spots to the south.
Hagar Mountain (near Mountain)
Approximately 78 miles from Green Bay · About 1 hour 35 minutes
This Wisconsin State Natural Area features dramatic exposed igneous rock outcrops, steep cliffs, moss-covered north-facing faces, and one of the few waterfalls on the Nicolet — and it’s also home to one of the northernmost and largest turkey vulture roosting sites in Wisconsin.
If you’ve never watched a group of turkey vultures lift off a rocky outcrop on a spring morning, put this on your list immediately. The habitat variety here — bare south-facing cliffs, hemlock-covered north slopes, and rugged talus edges — supports an interesting mix of species beyond the vultures too. The views from the outcrops are genuinely scenic, and spring is a fine time to visit before the canopy fills back in.
Cathedral Pines (near Townsend)
Approximately 78 miles from Green Bay · About 1 hour 35 minutes
Cathedral Pines is a remarkable 40-acre old-growth forest nestled within the Chequamegon-Nicolet National Forest — a rare survivor of Wisconsin’s logging era, featuring towering white pine, hemlock, and red pine. For birders, the primary draw is the great blue heron rookery nesting high in the canopy.
As you hike the trail, look up to spot the herons and their nests, and look down in May and early June for eggshells that have fallen near the trail — they look like giant robin’s eggs. A note on timing and etiquette: visitors should be very careful not to disturb the birds and rookery in the spring, as too much disturbance may cause the herons to abandon their nests.
Beyond the herons, Cathedral Pines is known for golden-crowned kinglets, hermit thrushes, and Blackburnian, black-throated green, and pine warblers — and red crossbills can turn up at any time of year. The trail itself is a short, gentle 0.3-mile gravel loop — an easy morning stop.
Directions: Take State Hwy 32 North 1 mile to Archibald Lake Road (FR 2121). Turn left (west) for 1.5 miles, watch for signs on the left, then turn right to the parking area. Parking for up to 5 vehicles.
Snow Falls Creek State Natural Area (north of Mountain)
Approximately 80 miles from Green Bay · About 1 hour 40 minutes
This 350-acre natural area is a reliable spot for Blackburnian warblers, least flycatchers, red-shouldered hawks, merlins, and ruby-crowned kinglets. Getting there takes a bit of navigation, but it’s worth it.
Directions: Drive east and north 3 miles on Cty F, then east 0.3 miles on Smyth Rd, south 2.3 miles on Sullivan Springs Rd (FR 2330), then drive or walk southwest 1.4 miles on FR 2944 to the Snow Falls Creek crossing.
Purple Martins: Keep an Eye Out Starting in April
Purple martins are one of the more charismatic spring arrivals, and they’re worth watching for across the county as April progresses. Scout martins — the oldest birds, returning to colony sites from the previous year — usually arrive in Wisconsin during the last week of March and throughout April. Sub-adult martins arrive around the first two weeks of May through late June. They’re aerial acrobats and tend to congregate near water, making the river corridors and Green Bay shoreline, like City Park in Oconto, good places to start looking.
A Few Tips Before You Go
• Download the Merlin Bird ID app (free, from the Cornell Lab of Ornithology) — it can identify birds by sound in real time, which is genuinely remarkable and makes spring migration a whole different experience.
• Check eBird.org before you head out — it’s a free tool that shows recent sightings by location and is the best way to know what’s been spotted in a specific area in the last few days.
• Wisconsin DNR has great resources as well.
• Early morning is almost always the best time for birding, especially for songbirds. The first two hours after sunrise are peak activity for most species.
• Bring binoculars if you have them — and if you’re visiting the harbor or marsh, note that viewing binoculars are available on-site.
• Respect nesting birds and give wildlife space, especially around known eagle nests and the Cathedral Pines heron rookery.
Happy birding!