State Route 257 (SR 257, OH 257) is a 26.19-mile (42.15 km) north - south state highway in the central portion of the U.S. state of Ohio. The highway's southern terminus is in the northwestern Columbus suburb of Dublin at a signalized intersection with U.S. Route 33 (US 33) and SR 161. This mainly two-lane highway follows the eastern side of the Scioto River from Dublin to its junction with US 42. After crossing over the river with the U.S. highway, SR 257 parallels the river's western bank. SR 257 has its northern terminus at a T-intersection with SR 47 on the western village limits of Prospect. SR 257 was created in 1926, and extended in 1935 and 1937.