[4] Construction of the extension from Fort William to Mallaig began in January 1897, and the line opened on 1 April 1901.

[9][10] In 1987 Roland Paxton, from Heriot-Watt University, investigated the legend that a horse had fallen into a pier during construction of Glenfinnan Viaduct in 1898 or 1899.

[11][12] However, after inserting a fisheye camera into boreholes made into the only two piers large enough to accommodate a horse, no animal remains were found.

[12] In 1997, on the basis of local hearsay, Paxton investigated Loch nan Uamh viaduct using the same method but found only rubble as well.

[11][12] In 2001, he returned to Loch nan Uamh with radar equipment and found the remains of a horse and cart within the viaduct's central pylon.