This article is about the Class III road numbered C51 maintained by Argyll and Bute Council. For other roads numbered C51, see C51.
The C51 runs around the north east corner of Tiree. It is not the coastal road, which appears to have been built within the last 50 years, but instead the road that runs north from Moss Church. This single track road runs past occasional houses set in rough fields to meet the coast road at Hough. This is a TOTSO junction, where the road turns right to continue north to the Machir Village of Ballevullin. This is a pretty village of scattered white cottages sitting in the sandy meadows of the Machir, a riot of colour in spring and early summer when the flowers are all in bloom.
The road again TOTSOs to the right, now heading east across the Machir, the houses sitting back from the road with few garden fences, the grassy machir providing all the garden most people need. After kinking around the north of Loch Bhasapol, the road comes to an end at a crossroads with the B8068 by Tiree's High School. The B8068 used to include two spurs here, so including all four arms of the crossroads, but this has now been changed.