(This branch forms a footpath "rail trail", the lower section of which has been resurfaced and supplied with heritage notice-boards.)

The NWNGR had originally built a 1 ft 11+1⁄2 in (597 mm) narrow-gauge line from a junction with the 4 ft 8+1⁄2 in (1,435 mm) standard gauge London and North Western Railway line at Dinas to Bryngwyn with a branch from Tryfan Junction via Waunfawr to Llyn Cwellyn (Snowdon Ranger).

In 1902, the newly formed PBSSR took over the failed Portmadoc, Croesor and Beddgelert Tram Railway with the aim of extending it to South Snowdon slate quarry in the Nant Gwynant Pass.

It was originally drawn up by the local Caernarfonshire authorities and aimed to link the PGSSR and NWNGR but had been delayed by the First World War.

According to the historian Peter Johnson, this would become a burden as the railway needed to generate the unlikely sum of £3,750 profit each year to service the debt.

[7] As there was no provision for the Ffestiniog Railway Company to hand back its lease and the WHR was bankrupt, the line became dormant.

The Croesor Tramway section was left intact in case the slate quarries re-opened and remained until finally lifted in 1948–9.

[7] In 1943, the Ffestiniog Railway surrendered its lease and, in exchange for £550 compensation, it was allowed to keep 'Single Fairlie' Moel Tryfan (although it only paid £150).

The Welsh Highland Railway's restoration has a long, complicated and controversial history and includes several court cases and public inquiries.

This group is the precursor of what eventually became WHR Ltd., which owns and operates the Welsh Highland Heritage Railway (WHHR).

[7] After a long legal battle between the two companies, the FR Co. won control of the WHR track bed and it re-opened the railway in stages, starting in 1997.

With Caernarfon Council having a longer-term plan to reinstate the town's rail transport link to Bangor, speculation mounted that the FR/WHR would potentially later extend itself.

The Pen y Mount to Pont Croesor section would then be handed over to the FR's construction company for incorporation into the rest of the WHR.

In the end, WHR Ltd was only able to build around a third of the way to Pont Croesor, with trains terminating at a location known as Traeth Mawr Loop (opened in 2007).

590 was planned to be part of a larger fleet to replace Moel Tryfan and Russell but it gained so little popularity that Stephens never bought another.

Moel Tryfan proved suitable, but Russell, even in cut down form, was not low or narrow enough to fit the FR's highly restrictive loading gauge.

The railway is a single track line with passing loops at Dinas, Waunfawr, Rhyd Ddu, Beddgelert and Pont Croesor halt.

As with any single track railway, there are strict rules managing the movement of trains to prevent more than one entering a section.

The line is managed from a single "Control" office at Boston Lodge Works, which also performs the same task for the Ffestiniog Railway.

The shunt token can only be withdrawn (used) with permission from Control and if there are no trains approaching the station in the adjacent single line sections.

A set of replica white wooden crossing gates separate the narrow-gauge line from the standard gauge track and continue the Network Rail boundary fencing.

A replica signal box was constructed for this crossing but has now been installed at Pen y Mount to control the junction with the Welsh Highland Heritage Railway.

During the year, operations were extended from Rhyd Ddu, first to Beddgelert on 7 April 2009,[20] and then to Hafod y Llyn on 21 May 2009,[21] site of a small halt on the original line.

Although passengers could board and alight at Hafod-y-Llyn, its remote location meant that it could only be accessed by self-sufficient walkers and cyclists as there were no parking or other facilities at the halt and the platform was very short.

Shortly thereafter the railway announced that as it had approval for service by the Safety Directorate of the Office of Rail Regulation (ORR), the remaining section would be completed before the end of September 2010.

[22] It was foreseen that this change in regime would bring additional costs to the railway, so it was decided to complete the line before that date.

On 30 October 2010 the first passenger trains, departing from Caernarfon to Porthmadog and return, were operated for the benefit of sponsors of the project.

[24] As a result of the A487 Porthmadog bypass works, the Ffestiniog Railway was severed just east of Minffordd station from 3 January to 16 February 2011 to build a new bridge.

[26] Although, with completion of the main track laying it is now possible to run trains from Caernarfon through to Blaenau Ffestiniog,[5] there are initially no plans to do so on a regular basis.

The WHR is built to a slightly larger loading gauge than the Ffestiniog Railway and therefore through trains would, of necessity, be exclusively of FR stock.