This article is about the Class III road numbered C677 maintained by DfI Roads. For other roads numbered C677, see C677.
The C677 starts on Melmount Road in Strabane and heads south west along Orchard Road, meeting the A5 bypass before long. The road continues south westwards on the other side of the bypass and into the countryside. The road crosses the B165 as it passes west of Glebe. Eventually the road turns more in a southerly direction before turning south west once again as it approaches Erganagh. On the edge of Erganagh a spur of the route heads north and reaches as far as the border, although the actual road briefly passes through County Donegal before returning to County Tyrone as an unclassified road. After passing through Erganagh the road meets the B72 and then crosses the River Derg. The road ends on the C672 at a T junction to the south.