wl ‘g 
WESTERN WHITE PINE AND LARCH-FIR FORESTS ll 
of moisture and the hot, dry winds blowing from the dry region 
' east of the Cascades. The fire danger is greatly increased by the 
fact that these winds blowing against the sunny slopes reach their 
greatest velocity during the hottest part of the day. In the Clear- 
- water region, where the summer winds blow parallel with the ridges 
and canyons, their drying, carrying, and fanning effect is still 
reater. 
ei The fire history of north Idaho forests is marked by a number of 
“peak years” in which unfavorable climatic conditions united to 
threaten widespread disaster. The seasons of 1889, 1910, 1914, and 
1919 stand out in particular. In addition, even the more favorable 
years have one or more brief but highly dangerous waves of extreme 
dryness. These critical periods can be forecast at present with only 
fair accuracy and then for only a short time in advance. 
To meet such conditions, a protective organization is demanded 
which must be not only efficient but thoroughly elastic—easily and 
quickly expansible to meet any emergency. 
CUT-OVER LAND PROTECTION 
A great difference in fire danger between uncut timber stands and 
cut-over areas is generally recognized. Any cutting increases the 
fire danger for a number of years, the period varying with the 
method of slash disposal. 
The annual fire season is much longer on the cut-over areas than 
in green timber. In green timber danger does not become critical 
until after considerable drought and high temperature, usually some 
time in July; but cut-over lands respond abruptly to changing 
weather conditions and not infrequently have serious fires in early 
May and even in April. The situation in the fall is similar. Rains 
early in September usually put an end to the danger of fire in green 
timber, while on cut-over or burned areas fires may continue to run 
several weeks longer. ‘The probable duration of the season on cut- 
over areas is roughly twice that in green timber. 
A quantitative comparison of inflammability is, of course, out of 
the question. One indication of the relation, however, is the state- 
ment of one of the timber-protective associations that in a five-year 
period 60 per cent of the burned area was on cut-over land, which 
constituted only about 10 per cent of the area protected. The rec- 
ords of another association for a five-year period indicate that only 
about 3 per cent of the class C fires (those over 10 acres) started in 
green timber and that they covered only about 1 per cent of the total 
acreage burned. It is evident, therefore, that to be equally effective 
action on fires on cut-over land or in old burns must be more prompt 
and more forceful than that required to protect green timber. 
As a rule, cut-over land is more exposed to special risk than is 
green timber. It is traversed by railroads or adjoins agricultural 
clearings; it is crossed by highways and is frequented by picnick- 
ers or berry pickers. Important also is the fact that the interest of 
the public in the protection of cut-over land has not reached a point 
where every fire is recognized as a matter of public concern. All in 
all the need of law enforcement and educational work is infinitely 
more urgent for cut-over land than for merchantable timber. 
