The station opened in May 1868 as the southern terminus of the 1 ft 11+3⁄4 in (603 mm)[14] narrow gauge Festiniog and Blaenau Railway (F&BR).

[16] In common with all other F&BR stations there were no platforms; carriages were very low to the ground, so passengers boarded from and alighted to the trackside.

In common with Tyddyngwyn and Tan-y-Manod stations, the only published photographs were taken from a distance, they lend the buildings the appearance of corrugated iron.

An apparently rudimentary shelter stood on the opposite side of the track; it served as a carriage and loco shed and repair shop.

A photo of a narrow gauge train at the station is reproduced in two significant works on the route without being captioned as being at that location in either.

[20][21] That the photo shows a train at Llan Ffestiniog is demonstrated by a much later shot in a third serious work,[22] and corroborated by local readers.

[28] The standard gauge station building, especially its double gable canopy without stanchions[29] and yellow brick signalbox with slate weatherboarding down one side,[30][31] were unlike any other structures on the branch.

[39] A fifth loop was provided between 1908 and 1950 immediately north of Cwm Prysor, when intermittent heavy military traffic to and from Trawsfynydd Camp was likely.

[46][47] Until 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.

"[56] During the war many works of art from galleries in London were stored in slate caverns at Manod, two miles northeast of Llan Ffestiniog.

A survey undertaken in 1956 and 1957 found that the average daily numbers of passengers boarding and alighting were:[71] Military traffic had ended and, apart from a finite contract to bring cement to Blaenau in connection with the construction of Ffestiniog Power Station,[72] 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.

[74] The station closed to passengers in January 1960 and to freight a year later, though the goods shed and booking office remained open for road-hauled traffic for some time further.

Few people used the service to visit the power station (most riders travelled "for the ride") so the following year tourist trains drove to the line's terminus then reversed, with no-one getting on or off.

A distinctive feature for people arriving at the station was the smell of "Morris Evans Oil" which was made in a shed next door.

As someone who travelled to the station once or twice a year put it: "It was a type of liniment, it stunk to high heaven but it was a legendary cure all in North Wales.

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."