U.S. organization for the conservation of natural resources, headquartered in San Francisco.
It was founded in 1892 by a group of Californians, including John Muir , who wanted to sponsor wilderness outings in Pacific Coast mountain regions. As its first president, Muir initiated the club's involvement in political action on behalf of nature conservation. With branches in all 50 states, it works to educate the public on environmental issues and lobbies local, state, and federal agencies for environmental legislation.