 Boise National Forest is managed by the U.S. Forest Service , an agency within the Department of Agriculture , as five units called ranger districts . The ranger districts are Cascade ( 400 @,@ 000 acres or 1 @,@ 600 square kilometers ) , Emmett ( 350 @,@ 000 acres or 1 @,@ 400 square kilometers ) , Idaho City ( 400 @,@ 000 acres ) , Lowman ( 400 @,@ 000 acres ) , and Mountain Home ( 650 @,@ 000 acres or 2 @,@ 600 square kilometers ) ; each has an office in their respective cities and is managed by a district ranger , while forest headquarters are located in the city of Boise . Congress proclaimed 2 @,@ 648 @,@ 273 acres ( 10 @,@ <unk> @.@ 18 km2 ) of Idaho part of Boise National Forest , but the forest manages only 2 @,@ 203 @,@ 703 acres ( 8 @,@ 918 @.@ 07 km2 ) . The proclaimed boundary is set and can only be changed by Congress whereas the administered boundary can be shifted among adjacent national forests without congressional approval . For management ( and from the visitor 's perspective ) the forest 's boundaries are its administered area . 
