Retsof is an unincorporated community within the town of York in Livingston County, New York, United States. The community, situated 26 miles (42 km) southwest of the city of Rochester, is roughly centered around the junction between New York State Route 36 and New York State Route 63. It lies approximately at co-ordinates 42°49′50″N 77°52′55″W / 42.830660085637°N 77.8820800781°W / 42.830660085637; -77.882080078125. It was founded by a man named Foster who reversed the letters of his name to name the town and was the site of one of the world's largest salt mines until its collapse in 1994. A new mine, the Hampton Corners mine, is located near Mount Morris, about 10 miles (16 km) to the southeast. The original population of Retsof was mostly of Italian origin; they lived in a company town where the salt mine owned the houses and a store and maintained the small village. In addition to the salt mine, there was a small railroad—the Genesee and Wyoming Railroad (G&W)—that took the salt to the "Main Lines" in neighboring towns. The G&W remains active today as a branch line of the Rochester and Southern Railroad.