(a) Public meetings, assemblies, demonstrations, parades and other public expressions of view may be permitted within a national wildlife refuge open to public use, provided a permit therefore has been issued by the refuge manager.

(b) Any application for such permit shall set forth the name of the applicant, the date, time, duration, nature and place of the proposed event, an estimate of the number of persons expected to attend, and a statement of equipment and facilities to be used in connection therewith.

(c) The refuge manager may issue a permit on proper application unless:

(1) A prior application for the same time and place has been made which has been or will be granted; or

(2) The activity will present a clear and present danger to public health or safety, or undue disturbance to the other users or resources of the area; or

(3) The activity is of such nature that it cannot be reasonably accommodated in the particular national wildlife refuge; or

(4) The activity conflicts with the purposes of the national wildlife refuge.

(d) The permit may contain such conditions as are reasonably consistent with protection and use of the national wildlife refuge for the purpose for which it is maintained. It may also contain reasonable limitations on the time and area within which the activity is permitted.