The rugged geography of the east coast forced the MNR into an unlikely shape. Rather than cut directly south along the cliffs, the line ran westwards from Ramsey to Kirk Michael and then south to a junction at St John's, where it could meet the Isle of Man Railway's Peel-to-Douglas line of 1873. Construction began in 1878 and the line was operated by the Isle of Man Railway until 6 November 1880, when the MNR took over its own running. From 1881, passenger services ran through to Douglas. The west coast section required serious engineering. The Glen Wyllin and Glen Mooar viaducts crossed deep cuts in the land. Above Glen Mooar, an embankment christened the Donkey Bank perched high on cliffs above the sea, and it was a chronic maintenance drain. It was the only stretch on the entire Manx system whose rails were laid in chairs rather than spiked directly to sleepers.

The line accumulated small eccentricities. Between Kirk Michael and Ballaugh, the MNR maintained a halt purely for the use of the Bishop of Sodor and Man at Bishop's Court. Its facilities consisted of a single wooden bench. The flat northern section had so many hand-worked level crossings that the protecting signals for one crossing sometimes stood beside the previous crossing up the line. Near Ramsey, a distinctive lattice girder span called the basket bridge crossed the Sulby River; it was renewed in 1914 and remains a landmark of the trackbed today. The MNR also had the only dockside track on the entire Manx railway system, allowing direct transfer between rail and ship at Ramsey. The dockside line opened in 1883 and was closed in 1952. Schemes to do the same at Douglas were often proposed and never built.

In 1880 the MNR acquired its third locomotive from Beyer, Peacock and Company of Manchester, a small engine numbered 3 and named Thornhill, built alongside the Isle of Man Railway's number 7 Tynwald in the same Manchester works. In 1885 the line needed more power for the mineral traffic on the Foxdale Railway and turned to Dubs and Company of Glasgow for an 0-6-0 tank engine. This powerful machine was numbered 4 and named Caledonia, and she remains the muscle of the Manx system today. In 1905 the MNR was absorbed into the Isle of Man Railway Company along with nearly 47 miles of track. The Ramsey route enjoyed a brief boom between the wars and after World War II, then declined with the rest of the system. The whole network reached crisis in 1966 with no services. The former MNR closed in 1968, and the last train, an oil tanker for the Ramsey power station, ran in April 1969.

Many station buildings along the line survive, repurposed as a village fire station, private dwellings, and museum displays. Ramsey itself has no railway structures left, but Lezayre, Sulby Glen, Sulby Bridge, Ballaugh's goods shed, Kirk Michael, and St Germain's all retain something. Remnants of the Glen Wyllin and Glen Mooar viaducts still stand. Level crossing lodges at Orrisdale, West Berk, and Ballavolley remain. The trackbed is now a footpath and bridleway, threading the same line through the dunes and pastures. Of the locomotives, Thornhill is in private preservation in the north of the island. Caledonia, restored in 1994 for the Snaefell Mountain Railway centenary, still runs on the Isle of Man Railway, commonly on Ultimate Driving Experience days. The original Foxdale Coach, with its first-class compartment specially for the mine captain William Kitto, was restored for the centenary in 1979 and remains in regular service today.