Historical Notes

Conservation easements go back more than 100 years. Developed as a means to protect ecologically, agriculturally or culturally valuable lands, their creation is closely related to the rise of the first land trusts in the United States, between the late 1880’s and early 1890’s.

In 2010, the Harvard Environmental Law Review published one of the most complete accounts of the development of conservation easements. Its author, Zachary Bray, traces their history together with that of land trusts.

Both concepts share their origins in the state of Massachusetts, where both the first conservation easement was created towards the end of the 1880’s, together with the first land trust was established in 1891 as The Trustees of Public Reservations.

The original objectives of both land trusts and conservation easements have remained fairly the same over time: On one hand, enabling private entities to protect lands in perpetuity and, on the other, making this possible without forcing the entity to purchase those lands.

Since then, both concepts have evolved separately albeit with similar histories, with major parallels in their periods of growth and popularity as Bray’s article elaborates. With a few exceptions in the 1930’s and 1950’s, conservation easements and land trusts didn’t really achieve great importance until nearly one hundred years later, toward the end of the 20th century.

Their exponential growth began between the 1980’s and 1990’s. Bray attributes this shift to changes in US tax code and to the creation of authority statutes, which granted legal authenticity to conservation easements.

This process accelerated in the 1960’s and continued into the 1970’s, reaching one of its highest growth spurts by 1975, when 16 states had already adopted statutes that allowed for the creation and retention of conservation easements.

Two events played key roles in the history of conservation easements and the parallel boom in land trust creation.

The first took place in 1981, when the Uniform Law Commission drafted a federal statute concerning conservation easements, titled the Uniform Conservation Easement Act. The other one happened in 1986, when the federal government issued an explanation regarding the allowed tax deductions for conservation easement donations under the Internal Revenue Code.

Once the tax benefits for conservation easements were formalized, the amount of land trusts skyrocketed, and today there are more than 1,700 across the United States.

Of these, only 254 of these are officially accredited by the Land Trust Accreditation Commission, a Land Trust Alliance (LTA) program in charge of evaluating and certifying land trusts in order to ensure they meet the best conservation practice standards. The Conservation Trust of Puerto Rico has had this accreditation since 2012.

According to the LTA, conservation easements make up 18% of all lands protected by local, state and national land trusts in the United States. This amounts roughly to 8,833,368 acres of the total 47,021,499 acres protected by land trusts.

For all of this, land trusts and conservation easements remain to this very day as two of the most powerful tools for nature conservation.

References and Recommended Reading

Bray, Z. 2010. Reconciling Development and Natural Beauty: The Promise and Dilemma of Conservation Easements. Harvard Environmental law Review, Volume 34, Number 1, 119177. Taken from:

Chang, K. 2011. The 2010 National Land Trust Census Report. Land Trust Alliance, Washington D.C. Taken from:

Information about conservation easements on the Land Trust Alliance website:

National Conference of Commissioners on Uniform State Laws. 1981. Uniform Conservation Easement Act Summary. Uniform Law Commission, website:

Website for the Land Trust Accreditation Commission: