[11] The line faced potential closure as part of the Beeching cuts in 1963[12] and again in 1995 due to reduced revenues.

The branch to Oban diverges at Crianlarich, an important Highland junction of both road and rail, and runs through Glen Lochy to Dalmally and through the Pass of Brander to reach salt water at Taynuilt and Connel Ferry before a final climb over a hill to Oban.

Carrying on northwards, the line descends above the shores of Loch Treig and through the narrow Monessie Gorge.

With the exception of the route between Glasgow Queen Street and Helensburgh Upper, and the short section between Fort William Junction and Fort William station, the railway is signalled using the Radio Electronic Token Block, controlled from the signal box at Banavie station.

[18] During the summer season from May until October a steam locomotive-hauled daily return service between Fort William and Mallaig known as The Jacobite is operated by West Coast Railways.

From Oban ferries sail to the islands of Lismore, Colonsay, Coll, Tiree, Mull and Barra.

As of 2021, there is a single regular freight operation on the line, consisting of alumina services from North Blyth to a smelter near Fort William.

A further issue is finding suitable timetable paths for Oban & Mallaig trains on the busy North Clyde line, which carries an intensive local stopping service.

The Caledonian Sleeper travels at 40 mph (65 km/h) maximum, slowing down for a number of bridges on the route due to the heavy weight of the Class 67 locomotive which hauled the train until the end of the old franchise in April 2015.

Sleeper services to Fort William start, however, at London Euston, calling at Edinburgh Waverley and Queen Street Low Level (to pick up or set down depending on direction).