Idaho Code § 62-201
Every railroad corporation in this state must, within a reasonable time after its road is finally located, cause to be made a map and profile thereof, and of the land acquired for the use thereof, and the boundaries of the several counties through which the road may run, and file the same in the office of the secretary of state; and also like maps of the parts thereof located in different counties, and file the same in the office of the recorder of the county in which such parts of the road are, there to remain of record forever. The maps and profiles must be certified by the chief engineer, the acting president and secretary of such company, and copies of the same, so certified and filed, be kept in the office of the secretary of the corporation, subject to examination by all parties interested.
Idaho Code § 62-201