50 CFR § 35.5 - Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft, mechanical transport, structures, and installations.
Except as specifically provided and subject to existing private rights, there shall be no commercial enterprise and no permanent road within a wilderness unit, and except as necessary to meet minimum requirements for the administration of the area (including measures required in emergencies involving the health and safety of persons within the area), there shall be no temporary road, no use of motor vehicles, motorized equipment or motorboats, no landing of aircraft, no other form of mechanized transport, and no structure or installation within any such area.
(a) The Director may authorize occupancy and use of a national wildlife refuge by officers, employees, agencies, and agents of Federal, State, and county governments to carry out the purposes of the Wilderness Act and the Act establishing the wilderness and will prescribe conditions under which motorized equipment, mechanical transport, aircraft, motorboats, installations, or structures may be used to meet the minimum requirements for authorized activities to protect and administer the wilderness. The Director may also prescribe the conditions under which such equipment, transport, aircraft, installations, or structures may be used in emergencies involving the health and safety of persons, damage to property, violations of civil and criminal law, or other purposes.
(b) The Director may permit, subject to such restrictions as he deems desirable, the landing of aircraft and the use of motorized equipment at places within a wilderness where such uses were established prior to the date the wilderness was designated by Act of Congress as a unit of the National Wilderness Preservation System.