I see environmental activism, or at least involvement, as a key element in protecting the resources we enjoy in our outdoor activities. A site that focuses on the global environment is The Rainforest Site. A couple organizations I have supported off and on through the years are The Nature Conservancy and The National Arbor Day Foundation -- both seem appropriately focused on their respective goals and do not stray off into other political territory, which was the primary reason I stopped supporting the Sierra Club after only one year, and why I've never supported some other large, well-known environmental organizations.