Pearl River is a hamlet and census-designated place in the town of Orangetown, Rockland County, New York,United States. It is located east of Chestnut Ridge, south of Nanuet, west of Blauvelt, New York, and north ofMontvale and Old Tappan, New Jersey. The population was 15,876 at the 2010 census.
In 1696, Pearl River was originally part of a larger portion of land known as the Kakiat Patent that was granted to Daniel Honan and Michael Hawdon. In 1713, the land was split into north and south plots. After the Revolutionary War, the land was further divided and sold. Pearl River was a portion of land made up of woods and swamps originally called Muddy Creek. In the early 1870s, the town was divided into five different parts: Middletown, Sickletown, Pascack, Muddy Brook, and Naurashaun.There are conflicting accounts on how Muddy Creek came to be named Pearl River. According to some historians, a town resident named Dr. Ves Bogert found small pearls in mussels that thrived in Muddy Brook and, upon hearing this, Mrs John Demarest, the wife of the president of the New Jersey and New York Railroad, suggested the name "Pearl River" to her husband. Another account was that the name change was made to make the station stop sound more appealing on the railroad passenger schedules. The third account was that Julius E. Braunsdorf wanted to enhance the hamlet's business image by renaming it Pearl River.