Manganese was mined in Merioneth from at least 1823, it was an essential addition to the blast furnace in iron and steel manufacture. Graig Uchaf was owned at various times by the Merioneth Manganese Co. and the Dyffryn Mining Co. Ltd. It was worked until 1892.

Remains include shallow open workings, mostly overgrown by woodland. Underground workings, some accessible, have two lengths of rails in situ. There is a substantial loading bank.

Reference: GAT: Merioneth Manganese, 2007.

RCAHMW, 2009.