As summer comes to a close and fall begins, some may be struggling with the transition from cloudless skies and warm, sunny days to autumn’s constant cover and chill.

But mid-September may be the perfect chance to squeeze out one last day of outdoor adventure.

On Saturday, the Lehigh Gap Nature Center in Slatington will host its 17th annual Migration Fest, a free event that provides families the opportunity to explore the wonders of bird and butterfly migration occurring in proximity to their homes.

“We want people to be aware of this natural phenomenon that takes place in their own backyards,” said Chad Schwartz, who works as the program specialist at Lehigh Gap Nature Center.

What’s special about the spectacle taking place along Kittatinny Ridge, according to Schwartz, is the Blue Mountain itself. Schwartz called the ridge a “road-map,” and being the southernmost major Appalachian ridge in Pennsylvania, Kittatinny Ridge provides the proper climate for migration.

“The birds really depend on this one,” Schwartz said.

The celebration boasts a full itinerary, all of which begin or take place at the center’s Osprey House visitor and education center.

Starting at 9 a.m. Saturday, two events will kick off the Migration Fest: a field trip to Bake Oven Knob that will last until noon, where participants will be able to view the migration of birds of prey, and a bird walk for beginners and families that ends at 10 a.m.

Both binoculars and field guides will be present and accessible during each event.

Starting at 11 a.m., the first of two butterfly walks will begin. Nets will be provided, allowing participants to walk the grounds of the Osprey House and along the D&L Trail, catching and tagging butterflies in an effort to track them during their migration to Mexico. The second walk begins at 2 p.m.

More than its name suggests, Migration Fest doesn’t focus solely on animals’ seasonal exoduses.

Opening at 10 a.m. are a variety of exhibit tables featuring live reptile, amphibian and aquatic insect displays, and at noon there will also be an ecology scavenger hunt on the D&L Trail.

To see a full schedule of events, visit http://lgnc.org.