When the Empire defeated Konohagakure, it took heavy casualties and needed time to lick its wounds. Otogakure was quick to move and carve a swath of the Land of Fire for itself. As it became a major contender among the Shinobi World, Otogakrue postured to declare its lands the Land of Fire so that their leader could assume the title of Hokage (the Fire Shadow). Since then the lands controlled by Otogakure have been known as Fire Country North.
It is a temperate forest zone much like the lands surrounding Konohagakure.