The mill was built by the Welsh Crown Spelter Company, formed in 1899, and a subsidiary company of the English Crown Spelter Company (formed in 1883). The Welsh company worked a number of mines in the area, having purchased them from previous owners, notably what is today most-commonly known as Pandora mine (though known successively as Willoughby Lead Mine, Welsh Foxdale Lead Mine, and New Pandora Lead Mine), which lies about 1.5 miles south-south-east. The company also developed the small mine known as Klondyke, adjacent to where the mill was built. The company had grand plans for expanding the production of Pandora mine, which already had dressing floors immediately south of the lane (between Llyn Geirionydd &
Capel Curig). Most prominent in the scheme was the construction of a new, large dressing mill at Klondyke, to which the ore would be carried on a 2-mile tramway, before descending by aerial runway from the hillside above into the upper floor of the mill itself. Much of this tramway was level, and it is known that the company had a " gauge
Kerr Stuart petrol locomotive. access was shorter and more direct this way, crossing the
river Geirionydd by a bridge a short distance from the mill. Although the bridge platform has long been removed, the bridge parapets remain in good condition.
Klondyke mine showing Llyn Geirionydd in the distance, with Klondyke mill highlighted, with its prominent spoil heaps to the right Klondyke mine itself, which lay immediately adjacent to the mill, albeit on the other side of the river Geirionydd (really just a large stream at this point), consisted essentially of one main
adit heading south-east, directly below the line of the aerial ropeway into the mill. Although there is no evidence of a bridge today, there would clearly have been one, laid with rails, connecting the mine entrance with the lower storey of the mill - a distance of only some 40 yards. The mine had a brick-lined portal. A matter of yards beyond the portal, the adit splits into a number of very short levels, indicative of an intention to develop the mine in a number of directions. This, however, did not happen, for, inside, three tunnels head off to the right, all in a general southerly direction. The first tunnel is the longest, following the contour of the gorge at this point. Further in, the second tunnel is next in length, splitting into another very short tunnel right at its end. The third tunnel is the shortest, but all of these tunnels are ornate to a degree with mineral intrusion. As well as this mine, Klondyke mine was worked together with numerous smaller adit workings which lay a little upstream in Geirionydd gorge, although some of these latter working were strictly part of the Bryn Cenhadon Mine. ==Decline==