This mine was being worked in 1910 by R J Pugh with a workforce of 5
miners. In 1912 it was taken over by J B Walker and presumably later worked by
one of the larger companies before closing in 1928. At the time of writing, the
surface is being trenched to decide if it is worth reworking for the barytes,
which is reputed to be particularly pure.
Development was mainly by adits into the hillside and the ore was
transported by light railway round the northern side of the hill to a dressing
mill beside the road. The locomotive used here is believed to have been the
former Dinorwic Quarry engine "

At the mill, the ore was hand picked and washed. It was then ground
using 10 pairs of French burr stones with air float classification, producing
up to 200 tons per week of a 350 mesh product that was 99.7% barium sulphate.
The remains of some of these burr stones together with engine beds, can still
be seen.
This mine is split into two sections which lie east and west of
Cothercott Hill. On the west side, the concrete floor and loading bay of the
barytes mill are obvious features by the side of the road. Close inspection
will reveal two millstones near to the fence. A ramp leads up from the mill and
this connected with a loop of the light railway. This curved round the hillside
to the eastern workings and was operated by a steam locomotive. Four collapsed
adits can be made out on this side of the hill.
On the east side of the hill, No.6 Adit has collapsed a short distance
inside. Further up the hillside is a collapsed shaft and a trial adit. A trial
adit to the north-east is also collapsed. On the far side of the valley, No.10
Adit has run in. Along the hillside, No.8 Adit is still open and leads via
knee-deep water to an air shaft blocked with rubbish. Next to this is a deep
open working partly filled with rubbish. Just to the north, below the track, is
a small collapsed trial adit.
Over the fence is a collapsed drainage level, still issuing water, and a
flooded shaft. The latter had a wooden headgear which was lying on the ground
until it was removed in recent times. To the south-east is a collapsed adit
with a long cutting filled with brushwood. Further on is an open adit which
slopes steeply down to water, the workings below being flooded. On the hillside
above is a partly filled shaft.