Answer:
Idaho Fish and Game does not have a code or rule that specifically defines the distance you are required to be away from the road before discharging a firearm. However, Idaho Code 36-1508 (copied and pasted below) just explains that you cannot shoot from or across a public highway. If you are off the traveled portion of the road and you are not shooting across the road you are fine.
TITLE 36
FISH AND GAME
CHAPTER 15
PUBLIC SAFETY
36-1508.Shooting from public highway. No person shall:
(a) Shoot from Public Highway. Discharge any firearm from or across a public highway.
Answered on:
Wednesday, December 26, 2012 - 3:40 PM MST