Apr. is, 1925 Use of Liability Ratings in Forest Fire Protection 747 
Table XIII .—Average number of general risk fires per year, per million acres, by 
10-day periods —Continued 
REGION 3—NORTHERN IDAHO 
Period 
Number of fires, by forest types 
Western 
yellow 
pine 
Douglas - 
fir and 
larch 
Western 
white pine 
Lodge- 
pole pine 
Spruce, 
hemlock, fir, 
cedar 
Sub- 
alpine 
Brush 
and grass 
Apr. 11-20. 
0.9 
21-30... 
* 
May 1-10_„_____ 
6.8 
11-20_ _ 
0.1 
0.2 
21-31. 
.9 
June 1-10__ __, 
.1 
.4 
11-20.__ 
.3 
.6 
6.4 
21-30. 
.9 
.1 
1.2 
1.6 
July 1-10 
.9 
.2 
0.9 
0.6 
11-20_ 
1.0 
4.2 
.9 
1.6 
1.7 
.4 
21-31_........ 
9.8 
5.7 
8.6 
2.8 
2.4 
4.4 
2.6 
Aug. 1-10_ 
6.2 
3.2 
13.0 
6.6 
7.2 
3.8 
1.8 
11-20............. 
8.0 
4.4 
13.2 
5.6 
6.4 
12.9 
5.7 
21-31 ..._ 
16.9 
5.3 
17.0 
2.8 
4.0 
10.2 
4.8 
Sept 1-10-_....... 
8.0 
1.7 
4.2 
4.8 
2.6 
1,3 
11-20 
1.8 
.1 
.6 
.3 
21-30. 
.4 
Danger periods A*>__ 
July 21- 
July 11- 
June 21-30; 
July 21- 
June 21-30; 
July 11- 
July 21- 
Sept. 20 
Sept. 10 
July 11- 
Aug. 31 
July 11- 
Sept. 10 
Sept. 10 
Sept-. 10 
Sept. 10 
Danger periods B h __ 
July 21- 
July 21- 
July 11- 
Aug. 1- 
Aug 1- 
July 21- 
Aug. 11-31 
Sept. 10 
Aug. 31 
Sept. 10 
20 
Sept. 10 
Aug. 31 
REGION 4—EASTERN WASHINGTON 
Number of fires, by forest types 
Period 
Western 
yellow 
pine 
Douglas 
fir and 
larch 
Lodgepole 
pine 
Spruce, 
hemlock, 
cedar, 
white fir 
Sub- 
alpine 
Grass 
and 
brush« 
May ll-20_ 
0.6 
21-31 
June 1-10 w. 
1.7 
0.5 
11-20 __ ... _ 
'2.8 
.2 
1.6 
1 2.0 
21-30..__—_- 
7.8 
1.2 
4.2 
1.6 
0.5 
2.0 
July 1-10 
7.8 
2.2 
4.2 
3.1 
2.3 
11-20 
6 2 
2. 7 ; 
2.3 
.9 
21-31-_— 
17.4 
4.9 
8.6 
9.2 
2.0 
Aug. 1-10—______ 
7.3 
4.4 
7.8 
2.3 
__ 
11-20.____—— 
6.2 
4.4 
'■ 
11.7 
1.4 
' 2.0 
21-31 —. —___.— 
11.8 
5.9 
' 12.6' 
18.7 
.9 
6.0 
Sept. 1-10——_—__ 
6.7 
1.9 
1 i___ 
3.9 
___ 
6.0 
11-20 _ _ _ _ . __ 
3.9 
1.6 
21-30-- v -- 
2.2 
- 
... 
.8 
.5 
6.0 
Oct. 1-10 _ __ _._ __ 
2.8 
.2 
11-20 _____ ....._ 
2.0 
21-31 
,6 
Nov. 1-1(1 
.6 
Danger periods A b ___________________ _ _ 
June 1- 
June 21- 
June 21- 
June 11- 
July 1- 
June 11- 
Oct. 10 
Sept. 10 
Aug 31 
Sept. 20 
Aug. 20 
Oct. 20 
Danger periods B 6 _______ 
June 21- 
July 21- 
Same eisA. 
July 1- 
July 21- 
Aug. 21- 
Sept. 20 
Aug. 31 
Sept. 10 
31 
Sept. 30 
b Danger periods A are the periods during which one or more than one fire occurs in 10 days.. Danger 
periods B are the periods within which three or more fires occur in 10 days, or two fires or more a week, 
e Data on area of this type very unsatisfactory, therefore figures are little better than a guess. 
