Question: In what mountain range does the river originate which serves as the backdrop for Wilderstein, a 19th-century Queen-Anne-style country house located in Rhinebeck, Dutchess County, New York, United States?

Context paragraphs:
Church of the Good Shepherd (Rhinebeck, New York): The Church of the Good Shepherd is a Roman Catholic parish church under the authority of the Roman Catholic Archdiocese of New York, located in Rhinebeck, Dutchess County, New York.  The parish was established in 1975; it was a mission of St. Joseph's Church (Rhinecliff, New York) from 1901 to 1975.  The church address is Good Shepherd Church, 3 Mulberry Street, Rhinebeck, New York 12572

New York State Route 402: New York State Route 402 (NY 402) was a state highway located within the village of Tivoli in Dutchess County, New York, in the United States.  It was assigned in the early 1930s and served as a connector between NY 9G and what was once a ferry landing on the Hudson River west of the village.  Although the ferry service linking Tivoli and the village of Saugerties was shut down in the 1940s, NY 402 continued to exist until 1980.  On April 1 of that year, ownership and maintenance of the highway was transferred to Dutchess County as part of a highway maintenance swap between the county and the state of New York.  The highway became part of an extended County Route 78 (CR 78), which had begun at the junction of NY 9G and NY 402 prior to the swap.

Kip-Beekman-Heermance Site: Kip-Beekman-Heermance Site is a historic archaeological site located at Rhinebeck, Dutchess County, New York.  The site includes the ruins of the Kip-Beekman-Heermance House built 1700 by Hendrick Kip, Patentee.  It was also the home of Col. Henry Beekman, Jr. later of his Grandson Col. Henry Brockholst Livingston (1757 - 1823).  It was destroyed by fire in the early 20th century.  The house was of such local prominence that Franklin Delano Roosevelt based the design of the Rhinebeck Post Office on the manor house and used the ruins for the stone construction of the building.

Rhinebeck (village), New York: Rhinebeck is a village in the town of Rhinebeck in Dutchess County, New York, United States.  The population was 2,657 at the 2010 census.  It is part of the Poughkeepsie–Newburgh–Middletown, NY Metropolitan Statistical Area as well as the larger New York–Newark–Bridgeport, NY-NJ-CT-PA Combined Statistical Area.

Hudson River: The Hudson River is a 315 mi river that flows from north to south primarily through eastern New York in the United States.  The river originates in the Adirondack Mountains of Upstate New York, flows through the Hudson Valley, and eventually drains into the Atlantic Ocean, between New York City and Jersey City.  The river serves as a political boundary between the states of New Jersey and New York, and further north between New York counties.  The lower half of the river is a tidal estuary occupying the Hudson Fjord, an inlet which formed during the most recent period of North American glaciation, estimated at 26,000 to 13,300 years ago.  Tidal waters influence the Hudson's flow from as far north as Troy.

New York State Route 308: New York State Route 308 (NY 308) is a short state highway, 6.19 mi in length, located entirely in northern Dutchess County, in the U.S. state of New York.  It is a major collector road through mostly rural areas that serves primarily as a shortcut for traffic from the two main north–south routes in the area, U.S. Route 9 (US 9) and NY 9G, to get to NY 199 and the Taconic State Parkway.  The western end of NY 308 is located within the Rhinebeck Village Historic District, a 2.6 sqmi historic district comprising 272 historical structures.  The highway passes near the Dutchess County Fairgrounds, several historical landmarks, and the Landsman Kill.

Henry Delamater House: The Henry Delamater House is a historic house located at 44 Montgomery Street (US 9) in Rhinebeck, Dutchess County, New York.

Wilderstein: Wilderstein is a 19th-century Queen-Anne-style country house on the Hudson River in Rhinebeck, Dutchess County, New York, United States.

Rock Ledge (Rhinebeck, New York): Rock Ledge is a historic estate and national historic district located at Rhinebeck, Dutchess County, New York.  The district encompasses five contributing buildings and five contributing structures on an estate developed between about 1904 and 1906.  The manor house is a three-story, Italian Renaissance style stone dwelling.  It consists of a central section with three-story projecting pavilions and a two-story wing.  It has multi-level, tile hipped roofs with overhanging eaves.  Also on the property are the contributing stone barn, stone carriage house, a stone stable, guest cottage, three stone pump houses, a stone foot bridge, and a cistern.  It was a private estate until 1945, after which it housed a vegetarian resort, and after 1961 a novitiate for the Marist Fathers and home to Rhinebeck Country School.

Little Nine Partners Patent: The Little Nine Partners Patent was the final patent granted (1706) in Dutchess County, New York, United States.  It was located in the northern part of the county, and comprises all or parts of the modern towns of Milan, Pine Plains, and North East.  Roughly triangular in shape, it was bounded on the north by Columbia County, on the south by the Great Nine Partners Patent (1697) and on the west by the Schuyler (1686) and Rhinebeck (1697) patents. Its eastern boundary was the area known as The Oblong, a narrow strip of land along the eastern edge of Dutchess County, bordering the state of Connecticut.

Supporting paragraphs: Wilderstein Hudson River
Answer: Adirondack Mountains