The Nature Conservancy (TNC) was founded as an international, nonprofit organization and works to protect ecologically important habitats. Its initial mission was to preserve biological diversity by saving lands and waters that are integral to the life of native species. In its methods, TNC takes a firm scientific approach to identify the areas in need of protection. It employs strategies such as conservation easements, legal agreements that restrict private land use in order to protect natural resources, while allowing landowners to maintain ownership of their land. Today, The Nature Conservancy is among the three biggest environmental protection organizations in the United States, along with the Sierra Club and Conservation International. It is active in over 30 countries and has succeeded in preserving over 473,000 km² of land worldwide.
- Birchard, Bill. Nature's Keepers: The remarkable Story of How the Nature Conservancy Became the Largest Environmental Organization in the World. San Francisco: Jossey-Bass, 2005.