The western boundary is a north south line from (roughly) Quelanup to Walpole.
The boundary with the Wheatbelt region to the north is an arbitrary division from Boscabel to Woodanilling to Dumbleyung to just south of Newdegate to south of Lake King.
The eastern boundary is from about the Frank Hann National Park in the north to Cave Point in the Fitzgerald River National Park, 13 kilometres west of Hopetoun in the south.
