[14] The station remained part of the GWR through the Grouping of 1923, passing to the Western Region of British Railways on nationalisation in 1948.

[19][20][21][22] The proximity of quarry and railway necessitated clear and precise arrangements for blasting, over which the railwayman in charge at the station had the ultimate veto.

[23] The conveyor belt was installed around 1940 to replace a 2 feet (610 mm) narrow gauge railway which had carried stone from the quarries to the "main line".

[24][25][26] The September 1959 timetable shows After the Second World War at the latest most trains were composed of two carriages, with one regular turn comprising just one brake third coach.

[31][32] Up to 1930 at the earliest such services used dedicated, lower standard, coaches which used a specific siding at Blaenau where the men boarded from and alighted to the ballast.

A survey undertaken in 1956 and 1957 found that the average daily numbers of passengers boarding and alighting were: Military traffic had ended and, apart from a finite contract to bring cement to Blaenau in connection with the construction of Ffestiniog Power Station[36] freight traffic was not heavy, most arriving and leaving Bala did so from and to the south and that to Blaenau could be handled from the Conwy Valley Line northwards.

Monies were made available to divert the route round the dam, but it was decided that improving the road from Bala to Llan Ffestiniog would be of greater benefit.

[44][45] The mountainous countryside around Arenig was of particular interest to James Dickson Innes who introduced his friend Augustus John to the area.

Although by 2015 no trace of the platforms and buildings remained, the site could be identified by pillars which were used for supporting the conveyor belt which ran from the quarry over the station to the stone crusher.

[48] When the railway closed the quarry lost its key customer and road transport proved costly compared with the erstwhile railborne arrangements.

On 21 September at least one regional newspaper reported that "Volunteers are set to start work this weekend on clearing vegetation from the trackbed between Blaenau Ffestiniog and Trawsfynydd."