 In 1923, SR 26 was designated on all of former SR 389 between Marietta and Woodsfield and west across the southern side of the state to Dunlop in Hamilton County (near Cincinnati).In 1927, as most of this extension had been co-signed with U.S. Route 50, SR 26 was truncated to SR 31 (modern-day US 33) between Athens and Chauncey with the remainder west of there signed as US 50 and SR 126 between Dunlop and Milford.Two years later, the southern terminus of SR 26 was moved to Marietta when the Athens–Marietta segment became a part of US 50N (now mostly SR 550).