When the grazing fee was first instituted on the forest reserves it was often referred to as a property tax. Permits quantified a certain number of AUMs, (animal-unit-months or the amount of feed required for one cow for one month,) as descriptive of a grazer's pre-existing rights of use. The grazing "tax" was based on the value of that level of use in AUMs as property. The term "tax" was used almost universally in newspaper reports in the west from 1905 for a decade or more. (The notion of grazing taxes is discussed at length in McCarthy Hour of Trial: The Conservation Conflict in Colorado and the West, 1891-1907 pp. 161-164.)
"Special use permits" for grazing had originally been issued in recognition of rancher's pre-existing possessory property interest. A "permit," as generically understood, presumes that the activity may be prohibited all together under such as the legitimate "police powers" of government. The "permit" normally prescribes the conditions of use to avoid or minimize harm to public peace, health or safety. As such, it is considered a conditional "privilege." Insofar as the "permit" prescribed rules and regulations for use of the range, it was characteristic of a conditional permit. Insofar as the right to obtain a "permit" was based on an underlying pre-existing possessory right of use, under equity, it was exclusive of "all the world," but the "sovereign."
In 1916, to counter assertion of ranchers that they "owned" their grazing permits, the Forest Service began to refer to grazing permits as only a "privilege" obtained from the Secretary of Agriculture. (See Annual Grazing Report, 1916, Rio Grande National Forest, Sec. 63, Region 2, Dr. 35, RG 95, National Archives.) As a further attempt to discourage recognition of rancher's claims of pre-existing rights, the Forest Service established a permit waiver system, whereby the permit reverted back to the Forest Service upon sale or transfer of the ranch. Although this divested any acquired property rights in the actual permit, it could not remove transferable pre-existing property rights and priority rights of tenure.
The Forest Service then reissued the permit to the new owner as a privilege granted by the federal government, asserting the power to renegotiate the current value of the underlying right by reduction of AUMs or other terms.