David Brower was one of the most ambitious and effective environmental activists of the 20th century. Brower first visited Yosemite National Park when he was six years old, and it sparked a life-long love for the outdoors; as he grew to adulthood, Brower developed a passionate interest in the preservation of America's wilderness. At age 21, Brower joined the Sierra Club, and in 1952, he became one of the club's executive directors, fighting in both the public and private sectors to protect unspoiled lands, maintain wilderness area, and prevent exploitation of national parks. Later in life, Brower also helped to found Friends of the Earth and the Earth Island Institute, and was instrumental in the creation of a number of national parks, keeping dams out of historic river sites, and establishing the National Wilderness Preservation System. Monumental: David Brower's Fight for Wild America is a documentary which offers a detailed look at Brower's life and work, and includes some of his own 16 mm footage of his favorite parks (Brower was a talented amateur cinematographer).