The ranges within the National Forests are used by the kind of stock for which they are best adapted except when this would not be consistent with the welfare of local residents or the proper protection of the Forests. For convenience in administration Forests are divided into grazing districts. A typical Forest is divided into from 4 to 6 districts which may be natural grazing units, natural administrative units (coinciding with the Ranger districts), or parts of the Forest used by different classes of stock or parts of the Forest having different lengths of grazing seasons. Each grazing district is also subdivided into smaller divisions, units, or allotments. These are usually natural divisions defined by topographic boundaries, such as ridges, mountains, streams, etc., or more or less artificial divisions determined by the class of stock which uses them. For example, cattle and horses ordinarily graze in the valleys along the streams, while sheep and goats graze the crests of ridges and the slopes of mountains and will cross none but shallow streams. Each range division or unit is usually given a well-known local name, such as "Duck Lake Unit" or "Clover Valley Unit." One or more stockmen may be allotted to such a unit, depending upon the size of the unit and the number of animals it can feed. If only one stockman uses it, it becomes an individual allotment. Usually a sheep owner with several large bands of sheep is allotted one large unit adapted to sheep grazing, while a large unit adapted to cattle and horses may be allotted to one large cattle owner or to two or more smaller owners. The manner in which sheep and goats are handled makes individual allotments both practicable and desirable. The boundaries of range allotments are usually well defined. In the case of sheep they are marked with cloth posters. In most Forests range allotments are fairly well settled. Each stockman gets with his permit each spring a small map showing his own range and the surrounding ranges. _Who Are Entitled to Grazing Privileges._ The Secretary of Agriculture has the authority to permit, regulate, or prohibit grazing on the National Forests. Under his direction the Forest Service allows the use of the forage crop as fully as the proper care and protection of the National Forests and the water supply permit. The grazing use of the National Forest lands is therefore only a personal and non-transferable privilege. This privilege is a temporary one, allowable under the law only when it does not interfere with the purposes for which the National Forests were created. It is non-transferable because it is based upon the possession of certain qualifications peculiar to the permittee. To understand these qualifications it is necessary to briefly look into the history of the grazing of live stock on the western grazing lands.