Between East View and Pocantico Hills, the NYC&N built a segment leading to a perilous 80-foot-high trestle over a marsh-filled valley.

[3] Because of the dangers of crossing the bridge, which often required that trains slow down to a crawl, the line was rerouted west around that valley in 1881.

The West Side & Yonkers Railway was leased to the NYC&N on May 1, 1880, extending the line south across the Harlem River to the northern terminal of the Ninth Avenue Elevated at 155th Street.

In the 1910s, the Interborough Rapid Transit Company (IRT) of the New York City Subway purchased the bridge across the Harlem River to move its elevated lines north into the Bronx, cutting the NYP back to Sedgwick Avenue.

The line lacked a direct connection to NYC's flagship station, Grand Central Terminal (GCT), which hurt ridership throughout its existence.

The Mohansic Branch near Yorktown Heights, originally built to serve a mental institution that was canceled by Albany, went first.

[6] Despite a legal battle by Yonkers residents which reached the United States Supreme Court to save it, the line was scrapped in December 1944.

The line lacked a second track, electrification, commuter parking and direct service to GCT, all of which the parallel Harlem and Hudson Divisions had, resulting in declining patronage.

Until 1962, when NYC's West Shore Railroad was upgraded, the Putnam served oversize freight trains, due to the lack of tunnels on the line.

The last customer was the Stella D'Oro bakery in the Bronx, which stopped using the railroad in 1989, after which Conrail wanted to sell the right-of-way to the city and Westchester to reduce its tax bill.

[10] The Metro-North Railroad uses the remaining stub near Marble Hill station to store maintenance-of-way and contractors' trains, and for material delivery in the vicinity of West 225th Street.

The Getty Square Branch still shows evidence of its existence, with vestiges of the railroad and stations, and neighborhoods exhibiting characteristics of transit-oriented development.

[13] Getty Square station, originally a head house and train shed, was replaced by an office building, which still stands and is ornamented on its exterior and in its lobby with images of locomotives.

The 3.4 miles (5.5 km)-long right-of-way is part of the trail system in Van Cortlandt Park, including the bridge that carried the branch over the Henry Hudson Parkway.

[14] A lot of the intrusions on the branch were from the expansion of outside storage from adjacent industries, which broke up the right-of-way in many places, especially in Yonkers.

[10] Private homes that once served the branch include the termini houses of the Park Hill station's adjacent funicular, on Undercliff at Park Hill Terrace,[15] and on Alta Avenue[16] north of Overcliff, and the home of the railroad's president, also on Alta Avenue.