Organized environmentalism began with the conservation movement in the late 19th cent., which urged the establishment of state and national parks and forests, wildlife refuges, and national monuments intended to preserve noteworthy natural features. Early conservationists included President Theodore Roosevelt, Gifford Pinchot, and John Muir, the founder of the Sierra Club. Conservationists organized the National Parks and Conservation Association, the Audubon Society, the Izaak Walton League, and other groups still active. After World War II increasing encroachment on wilderness land evoked the continued resistance of conservationists, who succeeded in blocking a number of projects in the 1950s and 1960s, including the proposed Bridge Canyon Dam that would have backed up the waters of the Colorado River into the Grand Canyon National Park.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.