(b) Except as specifically provided in this chapter, and subject to private rights existing as of January 1, 1975, there shall be no commercial enterprise and no permanent road within any wilderness area. There shall be no temporary road, no use of motor vehicles, motorized equipment, or motorboats, no landing or hovering of aircraft, no flying of aircraft lower than 2,000 feet above the ground, no other form of mechanical transport, and no structure or installation within any wilderness area, except under either of the following circumstances:

1. (1) It is necessary in an emergency involving the health and safety of persons within the wilderness area.
2. (2) It is the minimum tool necessary to meet the minimum management requirements.

(c) The following special provisions are hereby made:

1. (1) Within a wilderness area, measures may be taken as may be necessary for the control of fire, insects, and diseases, subject to conditions that the state agency with jurisdiction over the wilderness area may deem desirable.
2. (2) Nothing in this chapter shall prevent any activity by any public agency within a wilderness area, including prospecting, for the purpose of gathering information about mineral or other resources that the state agency with jurisdiction over the wilderness area has determined will be carried on in a manner compatible with the preservation of the wilderness environment.
3. (3) A state agency with jurisdiction over a wilderness area may authorize the collection of hydrometeorological data and the conduct of weather modification activities, including both atmospheric and surface activities and environmental research, which are within, over, or may affect wilderness areas and for those purposes may permit access, installation, and use of equipment which is specifically justified and unobtrusively located. Maximum practical application of miniaturization, telemetry, and camouflage shall be employed in conducting weather modification activities. In granting permission for the conduct of data collection and weather modification activities, the appropriate state agency may prescribe operating and monitoring conditions that it deems necessary to minimize or avoid long-term and intensive local impact on the wilderness character of the wilderness areas affected.
4. (4) Within a wilderness area, the grazing of livestock, where established prior to January 1, 1975, may be permitted to be continued by the present lessee or permittee subject to limitation by the terms and regulations that are deemed necessary by the state agency with jurisdiction over the wilderness areas.
5. (5) This chapter does not apply to the aerial stocking of fish or to the conduct of aerial surveys of wildlife species.
6. (6) A state agency with jurisdiction over a wilderness area may authorize measures that address environmental damage or degradation affecting wilderness character and resources if those measures are consistent with the minimum management requirements and only the minimum tools are used.
7. (7) Guidelines for the determination of the minimum management requirements and the minimum tool shall be adopted by regulation.