The Oykel Viaduct is directly to the south of Invershin station and north of Culrain station. It is a single track 280 foot truss viaduct with two masonry arches to the south and three to the north, 80 ft over the watercourse. Also known as the Shin Railway Viaduct. (The confluence of the Oykel and the Shin is to the north, the viaduct passes over the Kyle of Sutherland.) The viaduct was engineered by William Paterson and was built in 1867, the line being opened in 1868.
A pedestrian footway was added on the west side in the 1990s.
| Invercarron Bridge|
Lairg Oil Depot
Dalmore Signal Box
Dornoch Firth Crossing
|Location names in dark blue are on the same original line.|
|/ /1912||Sutherland Railway|
Oykel Viaduct strengthened for 'Castle' locomotives during 1912/1913.