DerryGill Wood was re-established in 2000 as a Government Millenium project. Each Irish family was "given" a native tree in various forests across the country. Along with the nearby woodlands at Derrycrag, Rosturra and Pollnaknockaun - some of which are now Nature Reserves - these woodlands comprise some of the last remaining fragments of what was once an extensive area of woodland in this region, known as Woodford Forest.
Derrygill derives from "Derry" or in Irish "doire", an 'oak grove or wood' and "gall", which translates as foreigner. Derrygill therefore means "(oak)wood of the foreigner". Ordnance Survey maps from the 1838-1840 shows Derrygill townland as densely forested, extensive commerical foresting since the industrial age deforested this area whilst the trimmings of the trees continued to provide for a now long gone iron industry (Local remnants are the "bay" and names associated with iron works.