Locomotives and rolling stock: 21 locomotives; 56 passenger vehicles; 304 goods vehicles
Head offices and locomotive works at Stranorlar
The Strabane to Derry line was completely owned by the Midland Railway Northern Counties Committee although it was operated by the CDJRC. At the height of its extension, the County Donegal Railways Committee operated the largest narrow gauge railway system in the British Isles. The railway was affectionately known as the "Wee Donegal".
Dieselisation
Under the management of Henry Forbes, traffic superintendent from 1910 to 1943, the County Donegal Railways became pioneers in the use of diesel traction. The first diesel railcar was built in 1930, although two further petrol-engined railcars were built before standardisation on diesel traction in 1934. Eight articulated diesel railcars were constructed by Walker Brothers of Wigan between 1934 and 1951, by which time virtually all passenger services were operated by diesel railcar. The railcars could only be driven from one end and had to be turned by a turntable to make a return journey. They also couldn't be worked in multiple, if two railcars were working back to back both required a driver. The railcars were incapable of hauling most freight wagons, so steam traction continued to be used on freight and excursion trains. The railcars were powerful enough to haul specially constructed trailers and some lightweight freight wagons, these special wagons were painted red to distinguish them from the heavier wagons which were grey. A diesel locomotive named Phoenix was also used, but due to the noisy and slow speed she spent most of her career shunting and built up a mileage of in its working life.
Closure
The Glenties branch closed in 1947, the Strabane-Derry line closed in 1954 and the rest of the passenger services ended on 31 December 1959. Much of the railway was closed on that date. Goods trains ran between Strabane and Stranorlar until 6 February 1960 In 1961, the two most modern diesel railcars were sold to the Isle of Man Railway.
Tourist attraction
Part of the line, which runs alongside Lough Finn near Fintown, has been re-laid as a tourist railway. The Donegal Railway Heritage Centre has been established and contains historic details and artefacts of the CDRJC. St. Connell's Museum, in Glenties has an extensive display of items from the railway. The Foyle Valley Railway in Derry housed numerous CDRJC artefacts, although their future has been uncertain since the museum closed in 2015.
In preservation
Several examples of CDRJC rolling stock has survived into preservation. Some examples are listed below by number, with their present location in brackets:
