The University of Illinois Extension will hold a free Fossils of the Illinois Valley program for community members from 5:30 to 6:30 p.m. Thursday, June 4, at the Princeton Public Library, 698 E. Peru St.

Participants will be able to learn about fossils found in the region and the Mazon Creek fossil beds. Attendees can also learn how fossils form, what the fossils reveal about ancient ecosystems, why the Illinois Valley is a paleontological site, notable regional fossils and the area’s geological history.

Registration is required. To register, visit go.illinois.edu/FossilPrinceton.

Early accommodation requests for access needs are encouraged. To make a request, email emhansen@illinois.edu or call 815-433-0707.