NEHL - A small local colliery was situated just north of Cockfield village through the 19th century, though had disappeared off the maps by the 1890s. Dean Colliery was very modest (hence noted as a mine), with 2 small shed-like buildings with a small shaft likely inside. It connected via tramway to the railway at East Butterknowle, though this was taken over by Gordon House Colliery in later years.

Nothing remains of the site today.