
THE AIR SEASONING OF WESTERN SOFTWOOD LUMBER 49 
; CALIFORNIA PINE REGION 
GENERAL CONDITIONS 
The California pine region includes the Klamath Falls district 
of south-central Oregon as well as the pine territory of California. 
It extends, therefore, from southern Oregon through the entire 
length of the Sierra Nevada Range in California and embraces both 
sides of that range and of the Coast Range northward from San 
Francisco. However, in spite of the diversity of weather conditions 
which such an extent of territory involves, the region as a whole is 
characterized by certain common climatic features which to a con- 
siderable degree unify its air-seasoning problems. The comparative 
monthly weather data presented in Figure 8 are a composite of the 
COYLARATIVE AIONTHLY WEATH LE? CONLYTIONS 
] ] if T | | 
Hee ACTIVE DRYING SEASO/VV 










FER CENT 
ALLATIVE 
SVL /L/ 7 


ZO 
GO 




OR 
TEMPERATURE 
or 150 








MWERACE DRYING FERIOLS FOC G2 STOCK PULLD 1h LUFLERLWT MONTHS 70 REA [6 FE CELT HUSTLE COTE 
APPR QMATE MOUSTUKE CONTENT OF THOMA MV ARDY STOCK By MONTITS 
PER CENT 
MUSTURE CONTENT \ ZO \78.\/6\/4\/2Z\/70\F | JO \/2\/76 \ 78 
AVERAGE MIGKLIP OFRAUSTURE By VOD STOCK 1M OUPVERE/V 7 SEASONS 
eee Wie ole be | aye [pele 
Fig. 8.—Graphic air-seasoning chart for the California pine region 



o x 
oe x 
oO ——— RELATIVE HUMIDITYS AMONTHLY MEAN 
=~ TEMPERATURE ----- ~~ MONTHLY MEAN 








relative humidities and temperatures encountered at several fairly 
representative points and are given simply that the reader may 
visualize the most striking regional features. In this area, as in 
the Inland Empire, distinct active and inactive drying seasons 
occur. However, the active period is of longer duration in the Cali- 
fornia pine region, and the extremes are less severe, particularly dur- 
ing the inactive season. This means relatively less difficulty with 
rate of drying and final moisture content, but makes for a longer 
seasonal period of stain danger. Conditions favorable to excessive 
drying are, also, present for a time each year. 
The lumber cut of this region is very largely pine. More than 
60 per cent of the annual production is composed of the western yel- 
