Hi Can anyone help me find out or how tofind out what colliery my great grandfather Sydney Yemm (of Viney Hill) worked in. Many thanks.

Mining Employment Records
http://www.forum.forest-of-dean.net/index.php?mode=thread&id=24462#p24482

A list and map of the various gales making up the Forest of Dean coalfield.
http://www.lightmoor.co.uk/forestcoal/Coalopen.html