NRDC - Natural Resourses Defence Council
40 West 20th Street, New York, NY 10011
Telephone: (212) 727-2700 Fax: (212) 727-1773
-The NRDC is the nation's most effective environmental action organization. We use law, science and the support of 1.2 million members and online activists to protect the planet's wildlife and wild places and to ensure a safe and healthy environment for all living things. (See our mission statement here.) Worth Magazine has named NRDC one of America's 100 best charities, and Charity Navigator has given NRDC four stars (out of a possible four).

Sierra Club
National Headquarters
85 Second Street, 2nd Floor, San Francisco, CA 94105 USA
Phone: 415-977-5500 Fax: 415-977-5799
The Sierra Club is America's most effective advocate for the environment and helps you protect the environment locally and globally. like 1.3 million of your friends and neighbors, you want:
a safe and healthy community in which to live; smart energy solutions to combat global warming;
an enduring legacy for America's wild places. Since 1892, the Sierra Club has been working to protect communities, wild places, and the planet itself. We are the oldest, largest, and most influential grassroots environmental organization in the United States. From community issues and action to lobbying on a national level, membership helps you take action where it's needed most. As a member you'll have opportunities to get involved with local chapters, as well as be part of the largest national network of environmental advocates. You'll have the satisfaction of helping preserve irreplaceable wildlands and wildlife. Your voice will be heard through congressional lobbying and grassroots action.

Massachusetts Audubon Society
South Great Road, Lincoln, MA 01773
(617) 259-9500
Not to be confused with the National Audubon Society, this state-wide group is one of the nation's oldest and most respected conservation organizations. On Nantucket, it owns sanctuaries on Hummock Pond and Sesachacha Pond, and conducts various research projects involving Nantucket's bird, plant, and animal populations. It is a nonprofit organization supported by membership dues and donations.

The Trustees of Reservations
Headquarters located at:
572 Essex Street, Beverly, MA 01915
(508) 921-1944
http://www.thetrustees.org/
A membership-supported, nonprofit organization, the Trustees' interests are state-wide. It was established in 1891 by the state legislature. On Nantucket, The Trustees is supported through the efforts of the Friends of Coskata-Coatue Wildlife Refuge, its local fund-raising unit. The Trustees own properties at Great Point, Coskata, and Coatue. Also, they manage and conduct research regarding endangered shorebirds that nest on Nantucket's beaches.

The Nature Conservancy
Massachusetts Chapter headquarters located at:
79 Milk Street, Suite 300
Boston, MA 02109
(617) 423-2545
http://nature.org/
An international membership-supported organization, The Nature Conservancy's mission is "to preserve plants, animals, and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive." The Conservancy has designated Nantucket as one of forty "Last Great Places," and is involved in establishing and maintaining a Geographic Information System database of the island's natural resources for use by conservation organizations and government agencies.