Resource gathering
From Blacksmith Master Official Wiki
Resource gathering is done in special areas which must be unlocked via the Mastery Tree. Workers in resource gathering areas have a stamina bar, which is decreased when they perform their tasks. Once their stamina runs out they will finish their current task and then sleep, recovering 10 stamina every 3 seconds. Workers will automatically sleep at the end of the day.
Resources gathered will be delivered to the warehouse the next day.
Oak Forest
The Oak Forest become available after unlocking it via the Mastery Tree and is where Lumberjacks work.
The Oak Forest has a separate list of items that can be bought and can only be placed in the central clearing:


