boondocks
From the Tagalog (Filipino) word "bundok" meaning mountain.  "Boondocks" became a part of American vocabulary during the American-Philippine War, during which mountainous terrain afforded the Filipinos a position of strategic advantage in fighting for their country's independence.  The boondocks served as a Filipino base of resistance while earning a word in everyday American language synonomous with "hinterlands."
During the American-Philippine War, the boondocks were highly contested terrain.