The road runs from Port Hastings (at the east end of the Canso Causeway) to a junction with the Cabot Trail at Margaree Forks on Cape Breton Island, a distance of 107 kilometres (66 mi).

[2] From Port Hastings (near the town of Port Hawkesbury), Trunk 19 follows the western coastline of Cape Breton Island through Judique to the village of Port Hood, where it turns inland to the northeast through Mabou.

From Mabou, the route continues back towards the coast at Inverness, then returns inland.

[2] Trunk 19 is still referred to locally as Route 19.

[3][4][5] The entire route is in Inverness County.