36 CFR § 2.23 - Recreation fees.
(a) Recreation fees shall be established as provided for in part 71 of this chapter.
(b) Entering designated entrance fee areas or using specialized sites, facilities, equipment or services, or participating in group activities, recreation events, or other specialized recreation uses for which recreation fees have been established without paying the required fees and possessing the applicable permits is prohibited. Violation of the terms and conditions of a permit issued in accordance with part 71 is prohibited and may result in the suspension or revocation of the permit.
(c) The superintendent may, when in the public interest, prescribe periods during which the collection of recreation fees shall be suspended.