THIS YEAR MARKS THE BICENTENNIAL of Prospect Hill Orchards, one of the Hudson Valley’s oldest farms. The farm has been owned and operated by the Clarke family continuously since 1817, when Nathaniel Clarke and his wife moved from Cornwall to settle on 55 acres in Milton. One of the first orchards in the region to utilize low-spray, integrated pest management (IPM) practices, the sixth and seventh generation family members now running the farm continue to experiment with organic growing methods. The property is a popular pick-your-own destination for thousands of visitors, who come for cherries, peaches and apricots in the summer, and apples and pears in the fall. The Clarke family will commemorate the anniversary with an on-farm dinner in August, with more events scheduled for fall.