Construction on a new expressway bypassing the estate to the north began in the late 1960s and was completed in November 1970, at which time NY 117 was realigned to follow the highway.

The route proceeds generally northeastward along Phelps Way, a four-lane expressway, bypassing Sleepy Hollow and Kykuit, the Rockefeller family's estate.

[3] As Manville Road, the highway heads past five residential blocks, connecting to the southbound direction of the Saw Mill River Parkway before entering Pleasantville's commercial center at Memorial Plaza.

After crossing the Metro-North tracks, the route continues east along several commercial blocks before turning to the northeast and entering another residential section of Pleasantville.

The road takes a generally northeasterly track away from the town line to the hamlet of Chappaqua, a community just 2 miles (3.2 km) from the center of Pleasantville.

Past Park Avenue, NY 117 continues north through Mount Kisco, changing names to Main Street ahead of the village's central business district.

Here, the route enters a junction with the western terminus of NY 172 (South Bedford Road) at the main entrance to Northern Westchester Hospital.

[3] As the route heads away from Main Street, it proceeds through a brief wooded, residential area before entering a commercial district surrounding Mount Kisco Commons.

Several businesses and an industrial complex follow after as NY 117 continues northeast through the northernmost part of Mount Kisco and into the town of Bedford.

Across the town line, the development along the route remains commercial as the road parallels the nearby railroad tracks and the Saw Mill River Parkway to the northwest.

About 2 miles (3.2 km) from Mount Kisco, NY 117 enters the hamlet of Bedford Hills, where the route initially serves residential neighborhoods.

[3] In the commercial center of the community, NY 117 serves the Bedford Hills Metro-North station before widening to four lanes as it crosses the railroad tracks and connects to exit 39 of the Saw Mill River Parkway.

For the next mile (1.6 km), NY 117 runs alongside the northern edge of the Saw Mill River Parkway as it heads through another residential part of Bedford Hills as a two-lane road.

[9][10] The portion of NY 117's original routing between Tarrytown and Pleasantville passed through the center of Kykuit, the estate of the Rockefeller family, and was designed to handle 1,900 cars per day.

[20] The study was completed in 1978, at which time the New York State Department of Transportation (NYSDOT) concluded that traffic would never become heavy enough along NY 117 to bring about a need for a bypass.

The route selected by the town of Bedford would begin at Harris Road and head north and east to the Saw Mill Parkway, which it would merge into.