36 CFR § 251.55 - Nature of interest.
(a) A holder is authorized to use and occupy only the land and structures and conduct only the activities specified in the holder's special use authorization. The holder may lease the authorized facilities and improvements to other parties only with the prior written approval of the authorized officer. The holder shall remain responsible for compliance of facilities and improvements leased to other parties with all the terms of the holder's special use authorization.
(b) All rights not expressly granted are retained by the United States, including but not limited to (1) continuing rights of access to all National Forest System land (including the subsurface and air space); (2) a continuing right of physical entry to any part of the authorized facilities for inspection, monitoring, or for any other purposes or reason consistent with any right or obligation of the United States under any law or regulation; and (3) the right to require common use of the land or to authorize the use by others in any way not inconsistent with a holder's existing rights and privileges after consultation with all parties and agencies involved. When costs can be feasibly allocated and have not been amortized, a new holder may be required to compensate existing holders for an equitable proportion of the original costs or other expense associated with the common use.
(c) Special use authorizations are subject to all outstanding valid rights.
(d) Each special use authorization will specify the lands to be used or occupied which shall be limited to that which the authorized officer determines: (1) Will be occupied by the facilities authorized; (2) to be necessary for the construction, operation, maintenance, and full utilization of the authorized facilities or the conduct of authorized activities; and, (3) to be necessary to protect the public health and safety and the environment.
(e) The holder will secure permission under applicable law, and pay in advance, the value as determined by the authorized officer for any mineral and vegetative materials (including timber) to be cut, removed, used, or destroyed by the holder from the authorized use area or other National Forest System land. The authorized officer may, in lieu of requiring an advance payment, require the holder to stockpile or stack the material at designated locations for later disposal by the United States.