The Sierra Club, a nonprofit nature conservation organization, has been at the forefront of battles to stop government-built dams in national parks. Led by David Brower from 1952 to 1969, the Sierra Club succeeded in preventing a dam from being built at Dinosaur National Monument, but failed to protect Glen Canyon, which was flooded to create Lake Powell. In the 1960s, Sierra’s fight to save the Grand Canyon from dams led to a compelling advertising campaign and a showdown with the Internal Revenue Service that galvanized the public to help protect the Grand Canyon.

Watch Film Excerpt: When The Sierra Club Saved the Grand Canyon

As Tom Turner, editor, Friends of the Earth and Earthjustice, puts it in this film excerpt, “People in the public may not have known what they thought about the Sierra Club; but they sure knew what they thought about the Internal Revenue Service. Sympathy for the Sierra Club just boiled over and people joined in droves.”

Public pressure changed the course of the government’s plans. Congress went on to expand the national park and prohibit dams anywhere within the Grand Canyon.

This is a film excerpt from A Fierce Green Fire. American Masters presents A Fierce Green Fire, the first big-picture exploration of the environmental movement, premiering nationally Tuesday, April 22, 2014, 9-10 p.m. on PBS (check local listings) in honor of Earth Day.