Idaho Code § 31-805
The board shall lay out, maintain, control and manage public roads, turnpikes, ferries and bridges within the county, and levy such tax therefor as authorized by law; provided that the board need not lay out, maintain, control, and manage public roads, turnpikes, ferries, and bridges inside the boundaries of a highway district formed pursuant to title 40 , Idaho Code.
[(31-805) R.S., sec. 1759; R.C., sec. 1917d, as added by 1913, ch. 143, sec. 2, p. 507; reen. C.L., sec. 1917d; C.S., sec. 3419; I.C.A., sec. 30-705; am. 1989, ch. 74, sec. 4, p. 129.]