It opened in 1904, providing access to a fairly remote area, and transport facilities for slate production and agriculture.

The Berwyn and Aran mountains (with steep gradients and sparse population) together formed a barrier for a through railway line westwards towards the coast.

Slate quarrying and agriculture were the area's dominant industries, and both suffered in the mid 19th century from transport difficulties.

One ambitious scheme was to extend the West Midland Railway through the region, passing through Montgomery and Bala, penetrating the Berwyns by a long tunnel.

The General Manager of the Cambrian Railways, Mr C. S. Denniss, estimated the capital cost of the line at £46,000.

[1] During the construction period, Strachan arranged to convey passengers free of charge on market days over part of the line.

Contemporary travellers reported: "The little six-wheeled engine ... was spinning along a quite a rate, considering its small wheel diameter; the carriage was a four-wheeled one, painted a dull red, and probably used at other times to convey the navvies to and from their work.

The passenger trains ran from Oswestry, southwards over the Cambrian Railways line as far as Llynclys, then turning west on the Cambrian Railways Porthywaen branch, leaving that at Porthywaen passenger station, a very small building, and now entering on the Tanat Valley line itself.

The track was of much lighter construction now, consisting of Vignoles pattern (flat-bottom) rails dogged direct to the sleepers.

Blodwel station had been opened in 1866, the terminus of the Potteries line, and known then as Llanyblodwel, part of the mineral branch crossing the path of the TVR.

A reservoir for Liverpool Corporation Waterworks was built at a location five miles away, and the railway was used for importing some construction materials.

It fell with a short section at 1 in 72 to Blodwel Junction, and then rose with a half mile at 1 in 64 but generally more moderate gradients all the way to the terminus.

[1] Mineral revenue was about twenty times the value of passenger receipts, and the latter declined further in the 1920s and 1930s as reliable road transport was developed.

[11] Opening its line in 1904, the Tanat Valley Light Railway Company was in the hands of the receiver continuously from that year,[6][12] as its income did not enable it to pay the interest on loans.

The Cambrian Railways subsidised it, but by 1921 it was obvious that improvements to the track and bridges were required, and this was beyond the financial resources of the bankrupt company.

The line west of Llanrhaiadr was closed completely in July 1952, a residual goods service continuing as far as that point for the time being.

This permits the CHR to reopen the route from Gobowen to Blodwel Quarry subject to level crossings of the A5 and A483 being replaced by a tunnel and overbridge respectively.

[19][20] The Nant Mawr visitor centre includes a nature trail, various picnic spots and a small museum.