Clue: Legal right allowing oriental fellows to occupy their quarter (8)
Answer: EASEMENT
Explanation: Definition: Legal right
An envelope ('to occupy') of E ('oriental') plus MEN ('fellows') in EAST ('their quarter'). As I have done a bit of trail work (hiking and maintenance) in my time, I am familiar with easement, in the form of the granting of the right to lay a trail across private land.