Oppenheim is a town in Fulton County, New York, United States. The town is in the southwestern corner of the county and is east of Utica. The population was 1,924 at the 2010 census.HistoryThe town was first settled around 1791 by Palatine Germans from Oppenheim, Germany. The town of Oppenheim was established in 1808 from the town of Palatine in Montgomery County before the formation of Fulton County. In the 1810 U.S. Federal Census, the name of the town was spelled, "Upenheim." When Fulton County was formed in 1838, the south part of Oppenheim was used to form the town of St. Johnsville, which remained in Montgomery County.The early occupations of townspeople were associated with dairy and cheese-making activities.GeographyAccording to the United States Census Bureau, the town has a total area of 146.2km2, of which 145.4km2 is land and 0.8km2, or 0.54%, is water.The northern part of the town is in the Adirondack Park. The west town line is the border of Herkimer County, and the south town line is the border of Montgomery County.