This abandoned railway line was organized in 1889 as the Walhonding Valley Railway (later to be known as the Pennsylvania Railroad's Walhonding Valley Branch). It was built to "kill" the dwindling Walhonding Canal, which it paralleled for most of its route. After construction of the line began in 1892 (then as the Toledo, Walhonding Valley and Ohio Railway), it caused much of a stir, due to PRR's unauthorized (illegal) use of land; the line was completed in 1893. In 1894, the PRR reached an agreement with the State of Ohio over the use of land, including the state's right to order the PRR to raise bridges for canal boats. The canal eventually closed in 1896, however.
The line was used until 1936, when the Mohawk Dam was built, cutting off the ROW.
Since then, most of the ROW has been obliterated, and the once-impressive 700-ft long, 70-foot high trestle over the PRR's Hudson-Columbus route, now abandoned, has long been removed. Portions of the ROW are visible via satellite imagery, though they can be challenging to locate.
Thanks to Aaron M. for contributing information about this route.