Marian Francis Thornton was born in Boston on September 14, 1933 and, while a resident of Newbury Court in Concord MA, died peacefully on February 24, 2019 surrounded by her family. She attended Winsor School and Smith College and worked in Brigham Hospital on blood research. She was known to many in the Conservation World and Concord, Massachusetts for her work in saving land for future generations to enjoy. She chaired the Concord Conservation Commission and the Concord Land Conservation Trust, and was on the Boards of the Massachusetts Audubon Society and the Trustees of Reservations. Marian received many awards for her work, including 1994 Conservationist of the Year award from the Trustees of Reservations, 1998 Charles Eliot award from Historic Massachusetts, 2000 Audubon A award from Massachusetts Audubon Society, and 2008 Honored Citizen award from the Town of Concord. She is survived by her husband Richard Thornton of Concord MA, daughter Margaret Webber and her husband Todd of Harvard MA, son Richard Thornton and his wife Toni of Los Altos CA, son Douglas and his wife Alison of Harvard MA, and seven grandchildren: Alex Webber, Kip Webber, Karen Thornton, Margo Thornton, Christopher Thornton, Arianna Thornton and Nicholas Thornton. Relatives and friends will gather for her memorial service on Saturday, June 22nd at 11 am in First Parish, 20 Lexington Road, Concord Center. As an Honored Citizen of Concord, the Concord Center flag will be at half-mast on this day. A private burial will precede the service at Sleepy Hollow Cemetery in Concord. Contributions in her memory can be made to Massachusetts Audubon Society's Drumlin Farm, 208 South Great Road, Lincoln, MA 01773 and the Concord Land Conservation Trust, P.O. Box 141, Concord, MA 01742. Arrangements are under the care of Dee Funeral Home & Cremation Service of Concord.