The Wagstaff Vein runs through the Carboniferous Limestone of Halkyn Mountain.

Remaining evidence of the workings includes very large or deep shafts, many of which are substantially capped with concrete beehives. These shafts are spread across an area on either side of the Rhes-y-cae to Halkyn Road and extend from north to south towards the quarry area. There are no associated structures, and the area was subject to a Prince’s Trust Award in 1978 for land reclamation.

A dried-up reservoir at SJ2000 7109 is likely related to the mining activities in this area.