Julia Butterfly Hill is an American environmental activist. She is best known for living in a 180-foot-tall, 1500-year-old California Redwood tree for 738 days between 1997 and 1999 in order to prevent loggers of the Pacific Lumber Company from cutting it down. She is the author of the book The Legacy of Luna: The Story of a Tree, a Woman and the Struggle to Save the Redwoods (2001) and co-author of One Makes the Difference: Inspiring Actions that Change our World (2002).