Code of Federal Regulations Title 36. Parks, Forests, and Public Property § 36.2.21 Smoking

(a) The superintendent may designate a portion of a park area, or all or a portion of a building, structure or facility as closed to smoking when necessary to protect park resources, reduce the risk of fire, or prevent conflicts among visitor use activities. Smoking in an area or location so designated is prohibited.

(b) Smoking is prohibited within all caves and caverns.