back forty vs beyond the black stump

back forty

noun
  • The most remote or inaccessible part of any place. 

  • The remote part of a farm. 

beyond the black stump

prep
  • In an extremely isolated place, remote from populated areas; in the middle of nowhere. Typically used to refer to outback areas. 

How often have the words back forty and beyond the black stump occurred in a corpus of books? (source: Google Ngram Viewer )