Scholar, biologist and author Dr. Robert Michael Pyle will be guest speaker at an Earth Day seminar, “People in Nature: Interactions on Mount Adams in a Warming Earth” on April 25 in the Columbia High School Gymnasium, 1455 N.W. Bruin Country Road, White Salmon, from 9 a.m. to 4 p.m.

Host is Friends of Mt. Adams (mtadamsfriends.org).