The A6139 is a short link road in Sowerby Bridge, Yorkshire. It was originally numbered B6139 and so was upgraded without a change of number in the 1970s.
The road starts at traffic lights on the A58 Wharf Street adjacent to Christ Church. It heads north along Tuel Lane, initially above a tunnel carrying the Rochdale Canal, which reappears by the first road on the left. In fact the original line of the B6139 followed the steep Tower Hill to the west. The gradient was lessened by building the present road along the abandoned line of the canal, necessitating construction of the tunnel when the canal was reopened in the 1990s.
After passing Lidl, Tower Hill comes in from the left, now only accessible on foot. The road steepens (signed as an 18% gradient) as it bends round to the right and passes a school. The road straightens out and continues to climb, soon ending at a T-junction on the A646 Barnsley Road, which is flat.