Mountaindale is a hamlet in the town of Fallsburg in Sullivan County, New York, United States, situated at an altitude of 1,010 feet (310 m). Mountaindale changed drastically in character from a rural farming hamlet, beginning with the arrival of the New York, Ontario & Western Railroad, and the name change of the local post office, in December 1880, from Sandburg(h) to Mountain Dale. Around that time a number of farmhouses that were more hotels than farms opened, and beginning in 1899 the ethnic character of the area began to change from predominantly gentile to predominantly Jewish.