The ruling issued Friday by U.S. Magistrate Judge Ronald Bush deals a blow for those who use all-terrain vehicles to explore the mountains and backcountry in eastern and central Idaho. The judge determined the plan written by federal forest officials failed to adequately protect natural resources and fully comply with environmental laws. The plan was challenged in court last year by a coalition of environmental groups. They argued the plan gave too much access to ATVs and other vehicles that can cause damage to established trails, wetlands, vegetation and stream banks.