The Sierra Club is the oldest, largest, and most influential grassroots environmental organization in the United States with more than three million members and supporters. It was founded in 1892 by the conservationist John Muir. The Sierra Club has hundreds of thousands of members in chapters located throughout the United States. The Hoosier Chapter has more than 10,000 members. Local Sierra Club groups are active in different parts of the state, working on conservation-related issues, sponsoring outdoor activities, and educating members on issues. Indianapolis (Heartlands), southwest Indiana, Greater Columbus (Winding Waters), and northwest Indiana (Dunelands) have active Sierra Club groups. Find your local Indiana group, and be sure to check out our events and outings page for more ways to get involved.