You must have quest 'Bult-kar: Cut at the Root.'
"Once one of the great lumber storehouses of Moria, Bult-kar has long since fallen into the domain orc and beast. The Iron Garrison, in need of supplies to fuel their reclamation efforts, see Bult-kar as a crucial location that must be brought back into the control of the dwarves."
This dungeon instance is full of resources such as:
Pile of Heavy Ilex Wood
Pile of Ilex Wood