(a) All grazing permits and grazing leases will specify grazing preference, except for permits and leases for designated ephemeral rangelands, where BLM authorizes livestock use based upon forage availability, or designated annual rangelands. Preference includes active use and any suspended use. Active use is based on the amount of forage available for livestock grazing as established in the land use plan, activity plan, or decision of the authorized officer under § 4110.3-3, except, in the case of designated ephemeral or annual rangelands, a land use plan or activity plan may alternatively prescribe vegetation standards to be met in the use of such rangelands.

(b) The grazing preference specified is attached to the base property supporting the grazing permit or grazing lease.

(c) The animal unit months of grazing preference are attached to:

(1) The acreage of land base property on a pro rata basis, or

(2) Water base property on the basis of livestock forage production within the service area of the water.