(a) The authorized officer will periodically review the grazing preference specified in a grazing permit or lease and make changes in the grazing preference as needed to:

(1) Manage, maintain, or improve rangeland productivity;

(2) Assist in making progress toward restoring ecosystems to properly functioning condition;

(3) Conform with land use plans or activity plans; or

(4) Comply with the provisions of subpart 4180 of this part.

(b) The authorized officer will support these changes by monitoring, documented field observations, ecological site inventory, or other data acceptable to the authorized officer.

(c) Before changing grazing preference, the authorized officer will undertake the appropriate analysis as required by the National Environmental Policy Act of 1969 (NEPA) (42 U.S.C. 4321 et seq.). Under NEPA, the authorized officer will analyze and, if appropriate, document the relevant social, economic, and cultural effects of the proposed action.