 SR 678 was designated in 1937.Originally, the highway was shown on the official state highway map as traveling along its current alignment between SR 374] and SR 180, then traveling along SR 180 west a short distance, and following what is now SR 374 from SR 180 to US 33 near Rockbridge.By 1938, however, SR 678 was shown in the form that it currently exists as today, with the remaining portions of what was identified as SR 678 on the prior year's map becoming a solo stretch of SR 180 and an extension of SR 374, respectively.