Coal mining is first recorded in the West Rainton area as early as the 15th and 16th centuries, although naturally outcropping coal seams along the banks of the River Wear may have been mined even earlier.

This early coal mining took the form of small relatively shallow shafts which once abandoned and backfilled can be seen on the surface as conical mounds around the shaft itself. Mallgill Wood contains some 76 such shafts together with the remains of a drift main and small scale opencast mining directly on the outcrop. These remains appear to have been long abandoned by the time the Ordnance Survey first recorded the site in the 1860s. In the late 19th century a deep mine was sunk towards the north-east corner of the wood. This mine known as Woodside Colliery but had a relatively short life and was closed in 1896. The coal mining remains in Mallygill Wood are Scheduled Ancient Monument protected by law.