David Brower, one of the most important and uncompromising environmentalists of the 20th century, died Sunday night at his home in Berkeley, Calif, at age 88. As the first executive director of the Sierra Club from 1952 to 1969, Brower helped shape the modern-day environmental movement by boosting the group’s membership from 7,000 to 77,000 (it now numbers 600,000) and winning battles to block dams in the Grand Canyon and set aside large portions of land as wilderness. He helped to popularize environmental causes by promoting successful coffee-table books by nature photographers like Ansel Adams and running full-page environmental ads in publications like the New York Times. Brower was a powerful writer and public speaker who inspired many to pursue environmental work. He left the Sierra Club after a power struggle and went on to help found Friends of the Earth and the Earth Island Institute. As longtime fellow crusader Tom Turner writes in Grist about Brower, "No one cared more."