|Successor||County Donegal Railways Joint Committee|
One of the first acts of the new company was to convert the former Finn Valley Railway from Strabane to Stranorlar from 5 ft 3 in (1,600 mm) to 3 ft (914 mm) gauge, which it completed on 16 July 1894.
Further new lines were built with a Government grant of £300,000 (equivalent to £34,700,000 in 2021),:
- Stranorlar and Glenties 24 miles (39 km), opened 1895 (stations: Stranorlar, Ballybofey, Glenmore, Cloghan, Ballinamore, Fintown, Shallogans and Glenties)
- Donegal Town to Killybegs 19 miles (31 km), opened 1893 (stations: Donegal Town, Killymard, Mountcharles, Doorin Road, Inver, Port, Dunkineely, Bruckless, Ardara Road and Killybegs)
Other extensions followed later:
- Strabane to Derry 14 miles (23 km), opened 1901 (station: Strabane, Ballymagorry, Ballyheather, Donemana, Cullion, New Buildings and Derry Victoria Road)
- Donegal Town to Ballyshannon 16 miles (26 km), was the last section to be completed and opened 2 September 1905  (Station: Donegal Town, Hospital Halt, Drumbar, Laghey, Bridgetown, Ballintra, Dromore Halt, Dorrian's Bridge Halt, Rossnowlagh, Friary Halt, Coolmore, Creevy, Legalton Halt and Ballyshannon)
In 1906 it was obtained by the joint interest of the Great Northern Railway of Ireland and the Midland Railway Northern Counties Committee which set up a new company, the County Donegal Railways Joint Committee.
- The Industrial Archaeology of Northern Ireland, William Alan McCutcheon, Northern Ireland. Dept. of the Environment, Fairleigh Dickinson University Press, 1984
- UK Retail Price Index inflation figures are based on data from Clark, Gregory (2017). "The Annual RPI and Average Earnings for Britain, 1209 to Present (New Series)". MeasuringWorth. Retrieved 11 June 2022.
- The County Donegal Railway, a Visitor's Guide by County Donegal Railway Restoration Society ISBN 1 874518 04 1