By the mid-nineteenth century, railways had reached even Inverness, but the northwest Highlands remained blank on the map. The terrain was either too soft or too rock-hard, there was no local labor or materials, and existing railway companies fought anything that threatened their monopolies. What changed government thinking was rural poverty sparking civil unrest -- as it had in Ireland. Funding was obtained, ground broken in 1889, and the line reached Fort William in 1894. The extension to Mallaig, completed in 1901, required the Glenfinnan Viaduct -- twenty-one arches of mass concrete, 100 feet high, built without a single piece of steel reinforcement. At Crianlarich, the new line crossed the older Callander-Oban route; after the Beeching cuts of 1965 severed the Callander section, the Glasgow-Oban service became a branch of the West Highland Line. On Rannoch Moor, a great boggy plateau, the track had to 'float' on wooden stretchers laid over the peat -- a technique that works to this day.

Rannoch station feels like the most remote railway halt anywhere, but Corrour -- the highest mainline station in the United Kingdom at 1,340 feet -- outdoes it. Corrour has no public road access; the nearest road is a ten-mile walk away by hill track. Until the late 1980s, its only electrical power came from batteries. It gained fame when it appeared in the film Trainspotting and again when the Harry Potter films used the route south to Rannoch as a location for the Hogwarts Express. At Bridge of Orchy, Bonnie Prince Charlie inadvertently did the locality a favor: the military road and bridge built after his rebellion in 1746 opened the area for the first time. At Spean Bridge, the parents of Australia's only saint, Mary MacKillop, once lived. The line threads through the Great Glen at its midpoint, turns southwest past Loch Lochy, and deposits travelers in Fort William beneath the bulk of Ben Nevis.

The Fort William-to-Mallaig extension, completed in 1901, contains the line's finest scenery. The Jacobite steam train, running daily from April to October, crosses the Glenfinnan Viaduct -- now famous worldwide as the Harry Potter bridge -- while below it the monument marks where Charles Edward Stuart raised his standard in 1745. At Loch Eil, the train passes through the heartlands of Clan Cameron, where 'the Gentle Lochiel' Donald Cameron's support was pivotal to the Forty-Five rebellion. At Loch nan Uamh, the Prince's Cairn marks where, on 20 September 1746, Charles fled back to France. The line reaches the sea at Arisaig, passes sandy beaches, and terminates at Mallaig, the small fishing port with ferries to Skye, the Small Isles, and Knoydart -- the last communities on the British mainland with no road connection to the rest of the country. The railway was never primarily a tourist attraction. It was a lifeline, and it still is.