750 
Journal of Agricultural Research voi. xxx, No. 8 
Table XIII .—Average number of general risk fires per year, per million acres , by 
10-day periods —Continued 
REGION 16—WEST SLOPE OF SIERRAS 
Number of fires, by forest types 
Period 
Western 
yellow pine 
Western 
yellow 
and Sugar 
pines and 
Douglas 
fir 
Red and 
white fir 
Lodgepole 
pine and 
subalpine^ 
Digger pine 
and oak 
Brush 
Grass 
Feb. 21-28/29_ 
0. 5 
0 . 2 
Mar. 1-10-. __ 
0.3 
11 -20-.-.. 
1>0 
. 1 
1 
21-31_ 
1 
Apr. 1-10__ 
11-20 _ 
.3 
21-30_ 
.2 
May 1-10._ 
. 1 
11-20 _ 
.8 
.2 
1.7 
21-31_ 
1. 3 
.4 
1 
1.0 
0.2 
1.7 
June 1-10_ 
3.1 
2.0 
1.5 
3.1 
1.3 
11-20 _ 
4.2 
1.3 
3.0 
0.3 
3.1 
.4 
3.4 
21-30_ 
1.0 
1 . 2 
. 6 
. 6 
1.7 
July 1-10_ 
3.9 
1. 3 
4.0 
1. 5 
13.6 
11-20 _ 
4.9 
4.4 
12.0 
.3 
4.4 
8.5 
21-31_ 
7.0 
4.5 
7.0 
.6 
1.0 
4.1 
8.5 
Aug. 1-10.._ 
9.4 
3.9 
8 . 5 
.8 
5.2 
5.7 
10.2 
11-20 _ 
10.4 
4.5 
7.0 
1.1 
2.1 
5.0 
10.2 
21-31_ 
14.8 
9.8 
16. 5 
2.2 
4.2 
8.3 
5.1 
Sept. 1-10_ 
5.2 
4.1 
6.5 
.6 
2.1 
5.2 
3r4 
11-20 _ 
7.3 
4.9 
7.0 
.6 
3.1 
5.2 
1.7 
21-30-...- 
12.0 
3.3 
6.5 
.6 
1.0 
3.5 
5.1 
Oct. 1-10_ 
4.7 
•f. 7 
3.0 
.3 
4.1 
3.4 
11-20 _ 
4.9 
1. 3 
1.0 
1.0 
2 . 6 
5. 1 
21-31_ 
2.9 
2 . 6 
1.0 
.9 
Nov 1-10_ . 
1.0 
. 6 
.5 
.. 
11-20 _ 
.3 
. 2 
1. 7 
21-30__ 
.3 
.2 
. 2 
1.7 
Dec. 1-10— _ 
. 2 
11-20 _ 
. 1 
1 
Danger periods 
May 21- 
June 1- 
June 1-20; 
Aug. 11-31. 
May 21- 
June 1- 
May 11-31; 
A.* 
Nov. 10. 
Oct. 31. 
July 1- 
June 20; 
10; Ju- 
June 11- 
Oct. 20. 
July 21- 
1 y 1- 
Oct. 20; 
Sept. 30; 
Oct. 20. 
Nov. 11- 
Oct. 11- 
31. 
31. 
Danger periods 
June 1-20; 
July 11- 
June 11—20; 
None. 
June' 1-20; 
July 11- 
June 11-20; 
B.& 
July 1- 
Sept. 
July 1- 
Aug. 1- 
Oct. 10. 
July 1- 
Oct. 20. 
30. 
Oct. 10. 
10; 21-31; 
Sept. 10; 
Sept. 11- 
Sept. 21- 
20 . 
Oct. 20. 
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. 
