North of the reservoir, NY 120 crosses the northernmost part of the Bronx River and traverses the northeastern corner of the town of Mount Pleasant, where the woods give way to a handful of residential neighborhoods. The transition in surroundings continues into the adjacent town of New Castle, home to housing tracts that become less isolated as the road veers westward toward the hamlet of Chappaqua. NY 120 proceeds west through residential and commercial areas to Chappaqua's central business district, where it meets the community's main north–south route, NY 117 (Bedford Road). NY 120 heads north through the center of Chappaqua, overlapping with NY 117 to reach another section of King Street one block to the north. Past NY 117, NY 120 continues generally westward through Chappaqua, changing names to Quaker Road a short distance east of Chappaqua's station on the Metro-North Railroad's Harlem Line.