The Trustees of Reservations is a non-profit land conservation and historic preservation organization dedicated to preserving natural and historical places in the Commonwealth of Massachusetts. It is the oldest land conservation nonprofit organization of its kind in the world and has 140,000 dues-paying members as of 2018. In addition to land stewardship, the organization is also active in conservation partnerships, community supported agriculture, environmental and conservation education, community preservation and development, and green building. The Trustees of Reservations own title to 120 properties on 27,000 acres in Massachusetts, all of which are open to the public; it maintains conservation restrictions on over 200 additional properties. Properties include historic mansions, estates, and gardens; woodland preserves; waterfalls; mountain peaks; wetlands and riverways; coastal bluffs, beaches, and barrier islands; farmland and CSA projects; and archaeological sites.
Main offices of the organization are located in Beverly, Leominster, and Sharon, Massachusetts. Financial support for the organization comes from membership dues, annual contributions, property admission fees, special events, grants, and endowments. In June 2006, The Trustees earned gold-level recognition from the United States Green Building Council for its Doyle Conservation Center in Leominster. In 2014, after seven years as an affiliate, the Boston Natural Areas Network merged with the Trustees of Reservations.