Ferncliff Forest is a 200-acre (0.81 km2) old-growth forest preserve of deciduous and hemlock trees located in Rhinebeck, a town in the northern part of Dutchess County, New York, USA. The property was bought by John Jacob Astor IV in 1900 and remained in the Astor family until 1963, when it was donated as a forest preserve and game refuge. The preserve is maintained by Ferncliff Forest LLC, a private, non-profit organization. Towers on the property were used for map-making, surveillance for President Franklin Delano Roosevelt's home during World War II, as well as recreational sight-seeing. Visitors can camp and hike the four miles (6.4 km) of trails free-of-charge.
The most recently built fire tower in Ferncliff Forest measures 80 feet (24 m) tall, with 109 steps. It was erected in 2007, the first since 1941 in New York. In 1942, the observation towers in Ferncliff Forest were manned by soldiers from the Army Air Corp 24 hours a day. The newest tower was constructed as a gift for the community for recreational purposes including hiking and mountain biking with an intricate trail system.
Before the establishment of Ferncliff Forest, individual farms made up the landscape of the east Hudson River. In 1853, William Backhouse Astor Jr. purchased several of these farms. His mother had grown up a few miles north of this property area in Rokeby. A neighboring property of 125 acres (0.51 km2) was owned by Thomas Suckley and hosted a farm colony. This property was later donated to the Methodist Church as a retreat for members of the clergy, becoming known as the Mount Rutsen farm colony.
When the colony was failing in 1900, 106 acres (0.43 km2) were sold to John Jacob Astor IV for $5,500, adding to the property that he already owned. After his death on the Titanic in 1912, the farm property was inherited by his son, William Vincent Astor who continued to expand the property by purchasing adjacent land. By 1940, William Vincent Astor had 2,800 acres (11 km2) reaching down to the Hudson River. After his death in 1959, Ferncliff Farm was left to his second wife, Brooke Russell Astor. She was asked in 1963 to donate the land for a forest preserve and game refuge. She donated the land in her will, requiring that it remain "forever wild".