In 1846 Greaves and his partner Edwin Shelton leased pasture land nearby at Llechwedd and began prospecting for slate.

In 1851 2,900 tons of finished slate was produced by Llechwedd and shipped over the FfR and the company moved its offices to Porthmadog, the terminus of the railway.

There a slate wharf dedicated to Llechwedd was built in 1853 where the quarry's products were trans-shipped to a fleet of sailing boats for transport to their markets.

In 1957, Llechwedd started shipping out finished slates by lorry to the wharves at the LMS station at Blaenau Ffestiniog, though this practice only lasted until 1962.

[1] Quarry operations continue at Llechwedd in 2013, though on a limited scale and using open cast mining techniques.

Llechwedd slate quarry has two hydro electric plants, the first opened in April 1904 at Pant yr Afon, and the second at Maenofferen in 1911.

[3] The early adoption of electric power at Llechwedd was down to Warren Roberts who was promoted to quarry manager in the late 1880s.