Roscoe is a hamlet in Sullivan County, New York, United States. The population was 541 at the 2010 census.Roscoe is in the southwest part of the Town of Rockland, adjacent to New York State Route 17.It is named for New York Senator Roscoe Conkling.Roscoe calls itself the "Trout Town, USA." The town is a destination for fly-fishing enthusiasts because of its location at the intersection of two rivers popular for trout fishing. The community is a traditional stopping point for people traveling along Route 17 because the facilities are right by the access road to the highway. These include gas stations and convenience stores.