Not only did The Nature Conservancy play a leading role in the policy arena for conservation easements, but the organization helped pioneer the concept of conservation easements, having accepted a donation of one of the very first conservation easements, in 1961, over land at Gallup Salt Marsh in Connecticut, just 10 years after the organization's founding.
The Nature Conservancy has been primarily engaged in the use of conservation easements that directly or indirectly protect the value of land and water as habitat for native plant and animal species.
Easements can be designed to:
- Protect natural habitat from destruction by conversion to other uses such as subdivision and development
- Protect open space of varying kinds from development or other disturbance
- Protect natural habitat from destruction by intensive agriculture
- Conserve forests through limitations on forest management and development
- Preserve agriculture and grazing lands from subdivision and development
- Protect water resources by limiting disturbance of lands in the watershed
- Provide for public use and access, such as through trail easements
For more than four decades, the Conservancy has been using conservation easements to protect more of a landscape from development than could be accomplished through outright purchase.
For instance, in the mid-1970s in Montana, at the request of local landowners, the Conservancy helped build the foundation of what would become the state's enabling legislation for conservation easements. Soon after, the Conservancy accepted a donation of a conservation easement covering 1,800 acres on the Blackfoot River in Montana – the state's first conservation easement.
Today some 30,254 acres in the Blackfoot Valley are covered by conservation easements, representing 50 miles of the river made famous in Norman Maclean's book, A River Runs Through It. It is one of the most intact, unfragmented landscapes in all of Montana. Across the state, 30 years later, conservation easements now protect some 1.4 million acres.
Of the 15.4 million acres protected by the Conservancy in the United States, more than 2 million acres have been protected through conservation easements granted to the Conservancy. The Conservancy has also assisted other U.S. land trusts and public agencies with conservation easements on an additional 1.3 million acres.
The use of conservation easements by land trusts across the country and increasingly in Canada, Latin America and Australia has escalated dramatically in the past decade. Today conservation easements are one of the most popular conservation tools employed by land trusts.