Question: The New York and Atlantic Railroad interchages in what hamlet and census-designated county of New York?
Context: Sterling Forest, New York is a hamlet in the Town of Warwick, Orange County.  It is served by an active United States post office of the same name.  It is situated on the eastern shore of Greenwood Lake, at the New Jersey state line.  Part of the hamlet extends into West Milford Township, Passaic County, New Jersey.  The hamlet grew up around the terminal station of the Montclair and Greenwood Lake Railway, later called the New York and Greenwood Lake Railway, and later the Greenwood Lake division of the Erie Railroad.  The railroad reached this point around 1875, with the station located at the state line in New Jersey.  The depot complex originally contained the Sterling Forest, New Jersey post office.  The post office was moved to the New York side of the line in 1926, where it continues to operate.  Rail service ceased in 1935. Chappaqua is a hamlet and census-designated place in the town of New Castle, in northern Westchester County, New York.  It is on 0.45 sqmi of land on the east bank of the Hudson River, about 30 mi north of New York City.  The hamlet is served by the Chappaqua station of the Metro-North Railroad's Harlem Line.  In the New York State Legislature it is within the New York State Assembly's 93rd district and the New York Senate's 40th district.  In Congress the village is in New York's 17th District. Union Station is a historic railway station located at Salisbury, Wicomico County, Maryland, United States.  It was constructed in 1913–14, near the junction where the New York, Philadelphia & Norfolk Railroad intersected with the Baltimore, Chesapeake and Atlantic Railroad in the center of Salisbury.  Both railroads became part of the Pennsylvania Railroad.  It has a 1 ⁄ -story, Flemish bond brick main block covered by a medium-pitched hip roof sheathed in slate, with single-story wings.  It was converted from a passenger station into a freight facility around 1958, and since 1986, used for other commercial purposes.  The building has characteristics of the Colonial Revival style and was the most elaborate passenger facility to survive on the Eastern Shore of Maryland. Jayville was a hamlet located in the southwest part of St. Lawrence County, New York, in the United States.  The hamlet started as a mining community in 1850 on what eventually became the Carthage and Adirondack Railroad.  Its existence was short lived as its non-favorable mineral composition and difficult ore availability was abandoned in favor of neighboring Benson Mines, located 14 mi down the railroad to the east.  After mining stopped in the community, other industries such as saw mills kept the population busy.  Ultimately, these business were short lived.  A further attempt to reopen the mines in 1914 failed and an eventual fire ended the existence of the hamlet of Jayville.  Today remnants of the hamlet can be found off the now abandoned railroad station located on New York State owned land southeast of Harrisville on Jayville Road. Yaphank ( ) is a hamlet and census-designated place (CDP) in Suffolk County, New York, United States.  The population was 5,945 at the time of the 2010 census. The Livonia, Avon and Lakeville Railroad (reporting mark LAL) is a short line railroad that operates in Livingston County and Monroe County in New York, United States.  The railroad interchanges with CSX at Genesee Junction in Chili, New York, the Rochester and Southern Railroad (RSR) at Genesee Junction and the RSR's Brooks Avenue Yard in Gates, New York, and with the Rochester & Genesee Valley Railroad Museum at Industry, New York.  Their primary freight consists of food products - grains and corn syrup.  In 1997, the Livonia, Avon and Lakeville Railroad was selected as Short Line Railroad of the Year by industry trade journal Railway Age.  The LAL is also the parent company for both the Bath and Hammondsport Railroad and Western New York and Pennsylvania Railroad. The Somerset Railroad (reporting mark SOM) is a railroad that operates in Niagara County, New York.  However, this railroad isn't part of its own company with its own motive power.  The railroad is sometimes mistaken as being classified as a Shortline, however it is not a shortline.  It is currently operated by CSX Transportation.  The railroad was built with the primary objective of providing coal to the Kintigh Generating Station, also known as the Somerset Power Plant, a 675 megawatt coal-fired power plant located in Somerset, New York.  The railroad was built in 1983 by the New York State Electric and Gas Co. using new and old rights of way.  From Lockport, New York, it runs on the defunct International Railway Co. (IRC) interurban line opened in 1900 under the name Buffalo, Lockport & Olcott Beach (BL&OB) which became part of the IRC in 1902.  From Newfane, New York, the SOM sweeps off the IRC (abandoned in 1937) to the Hojack Line in Appleton, New York (Township of Newfane, Niagara County, NY), to West Somerset in the Town of Somerset.  It then swings off on new trackage to a series of spurs and a loop at the Kintigh Generating Station. New City is a hamlet and census-designated place in the town of Clarkstown, Rockland County, New York, United States, part of the New York Metropolitan Area.  An affluent suburb of New York City, the hamlet is located 18 mi north of the city at its closest point, Riverdale, Bronx.  Within Rockland County, New City is located north of Bardonia, northeast of Nanuet, east of New Square and New Hempstead, south of Garnerville and Haverstraw village, and west, straight across Lake DeForest, of Congers.  New City's population was 33,559 at the 2010 census, making it the 14th most populous CDP/hamlet in the state of New York. The Catskill Mountain Railroad (reporting mark CMRR) , is a heritage tourist railroad based in Kingston, New York, that began operations in 1982.  While freight service was no longer offered, regular passenger excursions were operated on two sections of track separated by three washouts as a result of severe flooding.  The railroad leased the former New York Central Railroad Catskill Mountain branch from Kingston to Highmount, New York, where it connected with the Delaware & Ulster Railroad (D&U).  The railroad connected the Hudson Valley with the Catskill Mountains of New York State.  The corridor was purchased by Ulster County in 1979 from the estate of Penn Central and subsequently leased to Catskill Mountain Railroad in 1982.  The CMRR's lease with Ulster County expired on May 31, 2016 and the railroad ceased operations on that date.  On August 6, 2016, the CMRR resumed operations under a new permit agreement with Ulster county for two portions of the Catskill Mountain Branch in Ulster County.  In 2017, the railroad was awarded a five-year permit to operate trains on a five-mile segment of track from Kingston to West Hurley. The New York and Atlantic Railway (NY&A) (reporting mark NYA) is a short line railroad formed in 1997 to provide freight service over the tracks of the Long Island Rail Road, a public commuter rail agency which had decided to privatize its freight operations.  An affiliate of the Anacostia and Pacific Company, NY&A operates exclusively on Long Island, New York and is connected to the mainland via CSX's line over the Hell Gate Bridge.  It also interchanges with New York New Jersey Rail's car float at the 65th Street Yard and US Rail of New York in Yaphank, New York.  Its primary freight yard is Fresh Pond Junction in Queens.  The NY&A officially took over Long Island Rail Road's freight operations on May 11, 1997.  The initial franchise was for 20 years.
Answer: Suffolk County