FOREST SEEVICE. 237 



low-grade roads are built by the Forest Service, utilizing its field 

 organization of forest supervisors and rangers. 



To cany on highway work most efhciently it is necessary that the 

 progi-am be determined at least one year, and preferably two years, 

 prior to the beginning of construction. The program for the 1924 

 construction season is now under consideration but can not be defi- 

 nitely determiiied upon until the appropriations for the year are 

 known. Congress has recognized the adaptability of the legislation 

 contained in section 23 of the Federal highway act and has authorized 

 an annual appropriation of $6,500,000 for expenditure under the 

 provisions of that section for the fiscal years 1924 and 1925. 



A comprehensive study is now being made of the road needs of 

 the national forests under the two classes of forest roads specified 

 in the Federal highway act. The figures available indicate that to 

 complete the necessary system of forest development roads and 

 trails, 13,560 miles of roads and 37,114 miles of trails must be con- 

 structed, at an estimated expenditure of $64,693,000. For the system 

 of forest highways of primary importance to the States, counties, 

 and communities, the rough survey indicates that $107,658,000 

 must be expended for construction or improvement. If the present 

 current appropriations are continued, it appears possible to complete 

 the development of an adequate road system within the national 

 forests, covering all requirements, in from 20 to 26 years. 



MAPS AND SURVEYS, 



Accurate maps of the national forests are essential to every ac- 

 tivity conducted by the service. For the successful direction of forest- 

 fire detection and suppression it is vitally important that topographic 

 features and improvements such as ranches, telephone lines, roads, 

 trails, and other means of communication and transportation be 

 accurately delineated. Topographic maps are also needed in con- 

 nection with timber sales and the management of grazing business. 

 The increasing use of the forests for recreation has greatly multiplied 

 the demand for maps by the public. 



The foundation essentials for accurate maps are precise, detailed 

 topographic si^veys. These surveys are executed by the United 

 States Geologi'6ft»l Survey after the Coast and Geodetic Survey has 

 extended the necessary judiciary control. Small fragmentary 

 sections of the forests have from time to time been mapped by the 

 Forest Service in connection with timber sales or other activities 

 which require immediate data. The service cooperates with and 

 assists the Geological Survey in every possible way, including 

 financial aid whenever available, in surveying and mapping the 

 national forests. 



At present, of the 181,799,997 acres included within the forest 

 boundaries, 20 per cent is accurately mapped, and 56 per cent has 

 been covered by rough reconnaissance, leaving about 24 per cent 

 upon which no work has been done. This means that surveys ar*^ 

 needed upon 80 per cent of the national-forest areas to permit the 

 compilation of accurate and reliable maps. 



Ordinarily, maps are printed upon tliree scales — one-quarter, 

 one-half, and one inch to the mile, depending upon the available 

 and desired detail. All Forest Service men on field work carefully 

 check up errors which appear upon the maps, note corrections which 



