NY 275 begins at the intersection of Wellsville and Main streets in the
village of Bolivar. At this point,
NY 417 switches from South Main Street to Wellsville Street while NY 275 proceeds northeastward on the two-lane Main Street. The route initially passes by commercial buildings in the village's business district; however, they quickly give way to more residential areas after just two blocks. As the highway heads away from the village center, the homes become scattered ahead of intersections with the eastern terminus of
County Route 5A (CR 5A, named Salt Rising Road) and the south end of
CR 40 (Deans Flat Road). The rural trend soon reverses as NY 275 enters the adjacent village of
Richburg. Here, NY 275 is also known as Main Street as it serves Richburg's business district and the surrounding residential neighborhoods. Past Richburg, NY 275 continues on a northeasterly track through the rural town of
Wirt, running along the base of a narrow, largely undeveloped valley surrounding Little Genesee Creek as East Notch Road. The highway slowly increases in elevation for about , intersecting with the western terminus of
CR 8 (Inavale Road) and passing a handful of farms on its way toward East Notch, a gap between two large hills that serves as Little Genesee Creek's source. It eventually turns north to traverse the pass before winding its way down the opposite side. A short distance later, NY 275 intersects with the northern terminus of CR 8 as it curves to take a northwesterly track into the town of
Friendship. Just north of the town line, NY 275 enters the hamlet of Nile, where it becomes a two-lane residential street named Pennsylvania Avenue. In the center of the community, the route meets the east end of
CR 1 (Fifth Avenue). From here, NY 275 bends back to the north, crossing through rural sections of the town of Friendship mostly populated by farms. The rural surroundings end ahead of the
hamlet of Friendship, where NY 275 heads through the residential western portion of the community. Near the center of Friendship, the highway intersects
CR 20 (West Main Street), the primary east–west street through the hamlet. NY 275 continues on, crossing over the
Norfolk Southern Railway's
Southern Tier Line (formerly the
Erie Railroad's Main Line) to reach exit 29 of the
Southern Tier Expressway (
I-86 and
NY 17). NY 275 ends at the exit ramp leading away from the westbound direction of the freeway; however, NY 275's right-of-way continues north to
NY 19 in
Belfast as
CR 17. ==History==