Meldon Viaduct's wrought and cast iron trestles carried their first train on 12th October 1874. Built by Engineer W R Galbraith for LSWR's Lydford-Okehampton line, the track sat 150 feet above the valley on a rising gradient of 1 in 77 towards the west, incorporating a 30 chain radius curve.
Originally it was single track but, in 1878, was doubled by erecting a second viaduct on the south side, linked by extending the deck and bracing the tops of the trestles. The structure received additional strengthening before and during the Second World War.
In the late Fifties, the bracing of the Up trestle was replaced with stronger steelwork and it was this side of the viaduct which took the strain when the route over it was singled in April 1966.
The closure of the line in 1968 did not signal the end for Meldon Viaduct. In 1970, a road was laid across it to carry construction traffic to a nearby reservoir and, for almost 20 years, rail traffic continued to use it as a head shunt. But the structure was condemned in 1990 and the remaining track lifted.