NY 31's former alignment from Niagara Falls to Ridge Road via Sanborn became New York State Route 31A at this time.

The route heads east as Wheatfield Street, crossing the CSX Transportation-owned Niagara Subdivision at a grade crossing that separates an industrialized block of the street from more residential sections to the east.

North of this point, the closely spaced homes gradually give way to more isolated houses and, eventually, rural farmland.

[5] In terms of elevation, it reaches a crest of 644 feet (196 m) at Upper Mountain Road in Pekin before it begins to descend the Niagara Escarpment,[7] a beach ridge that further west led to the formation of Niagara Falls eons ago.

[8] Here, on clear enough days, a wide panorama can be seen of the entire northern half of the county and Lake Ontario.

[7] During this final, mostly undeveloped stretch, NY 429 passes the Buffalo Diocese's Immaculate Conception Catholic Church.

[11][12] In the late 1920s, NY 31 was realigned between Niagara Falls and the Lewiston–Cambria town line to follow Ridge Road west to the village of Lewiston.