Sandra Fales Hillman died unexpectedly and peacefully in her sleep on Friday, Jan. 20, at Stoneybrook, her home in Greenwich, Conn. She was 73.

Born on May 29, 1938, in Miami to Barbara (Bunny) Foote Fales and Sam Fales, Sandra was destined for a life of adventure as well as a prominent role as guardian of all of nature’s bounty — land, animals, birds and plant life.

As a young child and adolescent, she attended a school in Venezuela founded by her mother, but for a few winters, she lived in Barbados and attended a British school. There she began her lifelong love affair with horses and riding, taking long excursions on horseback with her mother along the beaches and in the plantations. Her father, a pilot, would fly over from Caracas to enjoy the weekends with his family. Sandra completed high school at Miss Harris’s Florida School for Girls before attending Smith College in Northampton.

She spent her childhood summers in West Tisbury at Windy Hill, the historic family property belonging to her grandparents Gladys and Warren C. Foote. During her marriage to Howard B. Hillman, she devoted all her winter weekends to skiing in Mad River Glen, Vt., while summers were spent at Waterwheel Farm in Chilmark. The farmhouse was a family base for raising their children, Howard and Elise, and the barn was the ideal setting for their scores of horses, hens, lambs, dogs, pet raccoons, skunks, cats, various amphibians and hives of bees. Last summer Sandra was ecstatic when a family of barn owls returned after an absence of two decades to nest in the barn owl box she had built many years before. Nightly, she would set out armed with a blanket and flashlight to watch the patient parents teach their fledglings to fly, urging her entire family and closest friends not to miss this experience.

In her early married years, while living in a carriage house in Brooklyn Heights, N.Y., Sandra cultivated her horticultural talents through an apprenticeship in bonsai training at the Brooklyn Botanic Gardens. Her passion for gardening, plants and the outdoors was instilled in her at an early age, inspired by her grandmother Gladys Underwood Foote, and by close mentors and family members Dora Butcher Hillman and Polly Butcher Hill, founder of the Polly Hill Arboretum. Another influence was her godfather, David Fairchild of Fairchild Tropical Gardens in Coral Gables, Fla., who instead of toys gave little Sandra glass jars filled with live bugs and butterflies.

Sandra honed her knowledge of gardening and horticulture by devoting hundreds of hours to Green Fingers, a garden club under the aegis of the Garden Club of America. She organized and led many memorable visits to world-class gardens, most recently in Quebec on the St. Lawrence River and another tour of special historic gardens in Charleston, S.C. She was honored with many awards for horticulture and conservation. In 1997 through Sandra’s efforts, the venerable Polly Hill was awarded the highly prestigious Garden Club of America medal of merit at the annual meeting in Philadelphia. Aunt Polly was 90 and Sandra wanted to see her recognized for her lifetime achievements. A family member who attended recalled it was a spectacular evening, with Polly sitting next to Edward Wilson, the ant scientist, heads bent in conversation.

As her mother before her, Sandra was a fluid and elegant equestrienne. Moving to Greenwich, Conn., in 1968, she trained with Teddy Wahl and Ray Molony of Round Hill Stables in the 1970s and 1980s. She was awarded numerous trophies for side-saddle, including winning the Cours d’Elegance for six years. She competed and placed in the National Horse Show at Madison Square Garden a number of times, and in 1980, she and her daughter were the first mother-daughter team to qualify in the side-saddle division at the Garden. She went on to share her knowledge and innate understanding of horses with many others — including her grandchildren, friends and the Pegasus Therapeutic Riding program for children with disabilities, where she not only volunteered but also served on the board.

Sandra was one of the first in Greenwich to embrace historic house preservation. With the purchase of Stoneybrook in 1973, she lovingly labored for hundreds of hours, restoring the property and gardens on the site of the 1750 Jeremiah Mead homestead and sawmill. In 2002, in collaboration with the Greenwich Land Trust and the Greenwich Historical Society, she succeeded in protecting her beautiful gardens and landscape through a perpetual conservation easement. Her dream was completed in 2006, when the Garden Club of America presented her with the Zone Historic Preservation Award, making Stoneybrook the first privately-owned single property in Greenwich to achieve this recognition. The gardens surrounding her home became a regular listing in the Garden Conservancy’s Open Days Directory — a guide to visiting gardens in America. Though she cherished her privacy and solitude, Sandra was happy to share this magical world she had created with family, friends and passers-by.

She found true peace on the Island, particularly at the farm on Middle Road. She valued her many deep friendships with Islanders with whom she rode horseback and hiked, and she devoted much time to the West Tisbury Agricultural Fair and the West Tisbury Congregational Church. She was also a board member for the Sheriff’s Meadow Foundation and a founder of the Friends of Middle Road Association. Keenly interested in her ancestry, she was anticipating the opportunity to further research the genealogy of her Cleaveland and Athearn forebears. In the last decade, she collaborated with her mother and sister on a three-volume set of memoirs entitled Venezuelan Ventures. The books brought vividly to life her parents’ adventures and the colorful years of a carefree childhood in Venezuela and the Vineyard. The accounts are treasured by all and gave Sandra a great sense of completion.

A descendant of Pilgrims, she lived her life simply and with devotion. She believed in work before play, and often said that we all need to touch the earth daily. She was at one with nature and animals. She was a true lady who epitomized the do-unto-others rule, always being a good neighbor and speaking well of others. She labored with love in her gardens and carefully reaped what she sowed — flowers, seeds, clippings, a jar of Concord grape jelly, honey, eggs, wool — all presented to the occasional visitor. She touched lives for a moment and made an indelible print. We will always see her emerging from the sparkling ocean waters of Quansoo, cantering over the crest of the hill in Hazelton, digging, weeding or clipping in her garden, or quietly reading outside as dusk falls.

She is survived by her daughter Elise Hillman Green and son Howard B. Hillman Jr.; her son in law Gregory H. Green and her cherished grandchildren, Hartwell, Ridgely, Harrison and Chandler Green. She is also survived by her sister, Barbara (Suki) Fales de Braganca of West Tisbury and Boston; her brother in law Miguel and their children, Miguel, Sam, Annabel and Camilla; her former husband Howard B. Hillman of Evergreen, Colo.; and her menagerie of pets, Bella the Australian shepherd, Archie the Shetland pony, three sheep named Baby, Doll and Blackie, 14 hens, and her cats Bambi and Simon.

Interment will be private on the Vineyard.

Gifts in her memory be made to either the First Congregational Church of West Tisbury, P.O. Box 3000, PMB 3111, West Tisbury, MA 02575, or the Martha’s Vineyard Horse Council, MVHC, Inc. P.O. Box 833, West Tisbury, MA 02575.