From this story in the Coeur d' Alene Press:
Idaho Fish and Game is seeking public comments on a proposal to apply motorized rule restrictions to trophy species hunts. Fish and Game is proposing to apply motorized restrictions to trophy hunts in game management units where restrictions already apply to big game hunts. Motorized vehicle restrictions were adopted to resolve many hunters' concerns about off-road travel. Typically, these rules restrict the use of any vehicle while hunting, including ATVs, ORV and motorcycles, to established roads open to a full-sized automobile. Hunters may use any motorized vehicle to retrieve downed game or to set up camp, if travel in the area is allowed by the land owner or manager.
Motorized vehicle restrictions can be applied to any big game hunt, including trophy species (moose, bighorn sheep and mountain goat). But the restrictions have not been applied to trophy species hunts. This has led to situations in which other big game hunters, such as elk, deer and bear hunters, were restricted in an area while trophy hunters, at the same time, could use motorized vehicles. A comment form is available on the Fish and Game website at http://fishandgame.idaho.gov/cms/public/._