THE NATIONAL FORESTS OF CALIFORNIA 25 



by white men were both common and extensive and more numerous 

 than the fires that occurred before their advent. This agrees with 

 the conclusions reached through the study of fire scars found in the 

 forests. 



Human agency was and is the chief cause of forest fires; and as 

 population increases, as industries such as grazing, railroading, and 

 lumbering develop, and as travelers increase in number, so does 

 danger from forest fires increase. To-day the rapidly expanding 

 industrial developments in the mountain regions and the ubiquitous 

 motor car bring into the forests an ever-increasing number of inex- 

 perienced travelers, unfamiliar with this malignant enemy of the 

 forests, and an increasing source of fire hazard. 



The Forest Service must oversee these users and educate them to 

 the care of their own property, and this task is becoming more 

 difficult each year. At the same time the forests themselves are 

 gradually becoming more difficult to protect and are also increasing 

 in value. Hazards are increasing as more privately owned stumpage 



PHOTO BY VAN MONTGOMERY 



AIRPLANE VIEW OF A FOREST FIRE 



Human agency is the chief cause of forest fires. Seventy per cent of all the fires that 

 occur in California are due to carelessness 



is cut without adequate disposal of the slash and debris. Stands 

 of young timber, the future sources of lumber and the most valuable 

 asset to conservation, are growing up and, being highly inflammable, 

 are subject to severe damage by fire. The population of the State 

 is growing rapidly, and the industries dependent on the forests, 

 such as water power, irrigation, grazing, and lumbering, are increas- 

 ing in economic value. It is clear then that both the value of and 

 the hazards to the forests of California are steadily becoming 

 greater. 



In the effort to handle adequately the task of forest protection the 

 Forest Service is continually improving its fire-fighting methods and 

 protective organization. Firebreaks, roads, trails, and telephone 

 lines are being extended; areas containing inflammable growth of 

 brush or other material of low forest value but of high tire hazard 

 are being cleaned up; the forest personnel is annually trained in 

 fire-fighting technic: studies are made of the causes of tires and the 

 best method of combating them; lookout systems are perfected and 

 the airplane and radio are called upon to help. Extensive cduca- 



