_Stock Associations._ The thirty or more grazing regulations effective on the National Forests are for the primary purpose of making the National Forest range lands as useful as possible to the people consistent with their protection and perpetuation. It is clearly impossible to meet the wishes and needs of each individual user, but it is often entirely possible to meet the wishes of the majority of users if made known through an organization. The organization of stock associations is encouraged by the Forest Service and the opinions and wishes of their advisory boards are recognized when they represent general rather than individual or personal interests. It is often possible through these organizations to construct range improvements such as corrals, drift fences, roads, trails, and sources of water supply for the common good of the members of the organization and paid for by them. _Protective and Maximum Limits._ In order to secure an equitable distribution of grazing privileges, the District Forester establishes protective limits covering the number of stock for which the permits of Class A owners will be exempt from reduction in the renewal of their permits. Permits for numbers in excess of the protective limits will be subject to necessary reductions and will not be subject to increase in number except through purchase of stock or ranches of other permittees. [Illustration: Figure 75. Sheep grazing on the Montezuma National Forest at the foot of Mt. Wilson, Colorado. Over 7,500,000 sheep and goats grazed on the National Forests during the fiscal year 1917.] [Illustration: Figure 76. Grazing cattle on a National Forest in Colorado. Permits were issued during 1917 to graze over 2,000,000 cattle, horses, and swine on the National Forests.] Protective limits are established to protect permittees from reduction in the number of stock which they are allowed to graze under permit below a point where the business becomes too small to be handled at a profit or to contribute its proper share toward the maintenance of a home. The average number of stock which a settler must graze in order to utilize the products of his farm and derive a reasonable profit is determined upon each Forest or, if necessary, upon each grazing district thereof, and serves as the basis for the protective limit. Protective limits have been established for various Forests running from 25 to 300 head of cattle and from 500 to 2,000 head of sheep and goats.