The line ran from a bay platform at
Haltwhistle, where it met with the
Newcastle and Carlisle Railway. From Haltwhistle, the line diverged south towards the
Alston Arches Viaduct over the
River South Tyne. The impressive stone structure, designed by
Sir George Barclay Bruce, is now
Grade II listed. Between
Haltwhistle and
Featherstone Park, there were two unadvertised calling points, at Park Village and
Plenmeller Halt. A platform was extant at Plenmeller Halt from the early 1920s until the late 1940s, however trains regularly stopped to allow passengers to board and alight long after the halt's official closure. No such facilities existed at Park Village. From Plenmeller Halt, the line climbed at a gradient of 1 in 70 to
Featherstone Park. At this point, the line passed close to the
Grade I listed Featherstone Castle. At
Coanwood, the line was 4 miles from the junction station at Haltwhistle. Before serving
Lambley, where the line met the
Brampton Railway until 1953, the line crossed the imposing
Lambley Viaduct. The
Grade II* listed stone structure, Trains regularly stopped to allow passengers to board and alight, despite no platform or facilities being situated at any of these locations. At
Slaggyford, the line is 8½ miles from Haltwhistle. Following the station's reopening in June 2018, Slaggyford now serves as a terminus of the
South Tynedale Railway. From Slaggyford, the South Tynedale Railway serves two intermediate stations at
Lintley Halt and
Kirkhaugh, both of which were purpose-built for the narrow-gauge railway. Crossing Gilderdale Burn Viaduct, the line leaves
Northumberland and enters into
Cumbria. Gilderdale served as another purpose-built intermediate station for the South Tynedale Railway from December 1986, closing when the line was extended to Kirkhaugh in September 1999. Alston Bridge serves as the final river crossing over the South Tyne, before reaching the terminus in the market town of
Alston, having climbed continuously from Haltwhistle to an altitude of about . ==Demise and closure==