Its eastern terminus is at State Route 93 approximately 2.75 miles (4.43 km) south of Oak Hill.

The two-lane highway passes through three counties along its path: Scioto, Lawrence and Jackson.

The route makes a quick hilly climb upward and downward to the former Teays River Valley near Slocum; it then traverses primarily wooded areas as it passes through Ashley Corner, Scioto Furnace, South Webster, and Eifort.

For most of its alignment, State Route 140 parallels an abandoned Baltimore and Ohio Railroad line.

The original routing of the highway is the one which it still utilizes to this day through Scioto, Lawrence and Jackson Counties.