Programs are free with park admission; $5. Call for reservations and more information.
A geologist explains how the Tucson Mountains and Santa Catalina Mountains separated in "Geology of the Tucson Mountains, at 2:15 p.m., Thursday Feb. 27. A biologist explains how saguaros provide shelter for wildlife and fights for survival in a 30-minute talk, "Living With Giants," at 10:45 a.m., Saturday Feb. 22. "The CCC in Saguaro National Park," a discussion of how the Depression-era Civilian Conservation Corps established the park's trails, picnic areas and scenic drives, is accompanied by old photos and film clips, at 2:15 p.m., Saturday, Feb. 22; wheelchair accessible.