The forest preserves are filled with fascinating sights, sounds and scents as spring emerges. Woodland wildflowers are beginning to bloom, hundreds of bird species are migrating through and nesting, frogs are calling, streams are babbling and insects return. What can you discover in your 43 Forest Preserves of Winnebago County?

Note: As a result of the updated stay at home order made by Governor Pritzker, beginning Friday, May 1, all forest preserve entrance gates will be open for limited daytime activities from 7 am until ½ hour after sunset. These activities include walking, hiking, equestrian, golf and fishing, including at Four Lakes Forest Preserve as long as social distancing is practiced.

Yellow warbler bird

First Week of May

This is the peak of bird migration! Over 320 species of birds have been documented here. Bird walks in the forests and fields of Winnebago County Forest Preserves are likely to turn up more birds than you ever knew existed! Many will soon be gone as they continue migration, while others "disappear" in the newly unfolding leaves of the tree tops. Call to request a free brochure, "Guide to Birding in the Winnebago County Forest Preserves."

Second Week of May

May begins the spawning season for largemouth bass. When water temperatures reach around 60 degrees Fahrenheit, the male begins construction and guarding of a nest. Bass spawn in water usually two to eight feet deep. The males will then spend the majority of their time and energy defending the nest, sweeping away sediment and guarding their young. During spawning, anglers often like to practice CPR--catch, photo and release-- ensuring the survival of the spawn. Sugar River Forest Preserve provides easy access for shore fishing for largemouth. The Kishwaukee River corridor forest preserves are favorites for smallmouth.

Third Week of May

Listen for frogs at mid-day. The Green Frog's banjo-like "gunk-gunk" calls are easy to tell from the "jug-o-rum" calls of the lookalike Bullfrog. Bullfrogs grow to be much larger than Green Frogs, and Green Frogs have long folds of skin lining the sides of their bodies. The Green Frog inhabits the shores of deep ponds during the spring and fall and moves into shallow ponds for the summer. A good place to see Green Frogs in the late spring and summer is the small pond at Severson Dells Forest Preserve and in the ox-bow ponds at Pecatonica Wetlands Forest Preserve. Camp at Sugar River Forest Preserve or Pecatonica River Forest Preserve and a chorus of frogs will sing you a lullaby!


Fourth Week of May

In Winnebago County, spring through early summer marks the peak of turtle nesting season. Snapping turtles may travel great distances from their native waters to lay eggs in warm sandy hillsides. Snapping turtles have a long neck and long tail. Snapping turtles and painted turtles are common sights in ponds and rivers. Two endangered turtle species make their home in forest preserves: Blanding's Turtle and the Ornate Box Turtle.

Find information and inspiration for experiencing spring's thrills at Also, check out for suggestions on outdoor activities and opportunities at parks, preserves, trails and natural areas throughout Winnebago County.