Apr. 15, 1925 
Use of Liability Ratings in Forest Fire Protection 
699 
9. Central Idaho and southwestern Montana. 
10. Yellowstone plateau region. 
11 . Black Hills and eastern Montana. 
12. Eastern Colorado. 
13. Northwestern Colorado and southern Wyoming. 
14. Wasatch and Uinta Ranges. 
15. Interior desert region—mostly Nevada. 
16. West slope of Sierras. 
17. Southern California. 
18. Colorado Plateau region. 
19. Northern New Mexico and southwestern Colo¬ 
rado. 
20- Southern Arizona and New Mexico. 
21- Lake States. 2 
values, fire hazard, and cost of sup¬ 
pression. The grouping of types within 
each region is shown in Table V. Such 
a classification is crude, it is realized, 
since it does not allow for such factors 
as age of stand or for the wide local 
variations in inflammability of indi¬ 
vidual stands of a given type, due to 
such factors as the presence of logging 
slash or other debris. Ratings ob¬ 
tained, therefore, will represent aver- 
Fig. 2.—Subregions used in studying fire hazard. (Region 21, Lake States, not shown) 
2. Within each of these regions it 
seems reasonable to assume that a given 
type of forest is in a broad way fairly 
uniform in its composition and general 
characteristics, so that within the re¬ 
gion classification of the forest areas ac¬ 
cording to type of cover will in a general 
way allow for variations in the factors 
which determine total and destructible 
ages of fairly broad application, but 
may not show what can be expected 
on individual small units. These fac¬ 
tors can be allowed for only when 
the fire records and the inventory 
of our forest resources include 
information concerning them. It is 
hoped that this can be done in future 
work. 
2 The study did not cover Alaska or the eastern national forests. 
