Timber reconnoissance (valuation survey or valuation strips) involves an estimate of the standing timber by small legal or natural subdivisions of land, with the necessary land surveys, the preparation of an accurate topographic and forest type map, and the compilation of detailed descriptive notes. These notes deal with the condition and character of the timber, the most practical methods of exploitation, the extent and character of the young growth, and many other factors which affect the management of timber lands. These data are secured at a cost of from 3 to 10 cents per acre, depending upon the accessibility and the topography of the region and the density of the timber. This work is carried on both in the summer and in the winter. Up to date, about 21,000,000 acres have been covered by intensive reconnoissance and about 48,000,000 acres by extensive methods. _Logging the Timber._ In order that my reader may better understand various matters connected with the disposal of National Forest timber, it will be necessary to give a brief outline of how timber and other forest products are taken from the woods, and the different steps necessary before a green tree in the woods becomes a board or a railroad tie. The methods of logging used in the National Forests are essentially the same as those used on private lands, with the exception of certain details, such as the protection of young growth, the cutting of snags, and the disposal of the brush. The methods used, of course, vary with the locality; they are different for the Pacific Coast, where donkey engines are used, than for the Rocky Mountains, where horses are largely employed. They vary with the climate, the topography, the size of the timber, and the kind of product to be harvested. But a typical logging operation, as carried on in the Sierras of California, will give an idea of how logs are taken from the forest. [Illustration: Figure 53. A large storage reservoir used to irrigate the ranches in the valley below. Elevation 10,500 feet. Battlement National Forest, Colorado. Photo by the author.] [Illustration: Figure 54. A sheep herder's camp used temporarily by Forest Service timber cruisers. Elevation about 10,000 feet. Battlement National Forest, Colorado. Photo by the author.]