CLIMATE AND VECETATION OP THE NORTH PACIFIC COAST REGION 
The rogion comprising Washington, Oregon and Northern California 
is divided into two distinctive sections by the Cascade Range, Siskl- 
yous and California Coast Range, The climate of the western section 
is determined by its position with relation to the Pacific shore, The 
range from moderate year round temperatures at the coast to prolonged 
frost periods of the high Cascades is uniformly related to elevation. 
Precipitation is generally abundant everywhere west of the suminit of 
those dividing ranges, but varies in intensity according to the loca¬ 
tion of intercepting mountains. 
The climate of the eastern section is similar to that of the con¬ 
tinental interior; changes in winter and summer temperatures tending 
to be extreme and often abrupt. Precipitation is light, and varies 
usually in relation to elevation. 
Vegetation appears to be closely related to topography. Duo to 
variety of topography m.any forest sites are reprosonted, and frost 
free periods range from 300 days to 30 days or loss, a truly remark¬ 
able variation in climatic conditions which has resulted in develop¬ 
ment of many climate races of trees of the same botanical genus and 
species, 
Magnificent stands of Pseudotsuga taxifolia (viridls) cover most 
of the western portions of V/ashington and Oregon, Intermingled with 
the douglas fir arc Thuja plicata (gigantea), Tsuga hetcrophylla and 
Abies grandis. In general the other Abies are found upon the higher 
slopes, above 500 meters. Along the coast is found Plcea sltchcnsls, 
from California to Alaska, Sequoia somporvlrons occurs along the 
coast of northern California; sequoia gigantea in the high Sierra. 
Plnus murrayana presents a v/ide range, from sea level to 1800 
meters. Pinus ponderosa ranges from slightly above^sea level to^2000 
motors or more. Those elevations are statoc. as limits v/ithin \irhich 
wo collect seeds in 1938. All species not specifically mentioned 
heroin are collected from the sources indicated in our price list, 
attached. 
For your convenience in ordering seeds wo hs,vc designated six 
source sites (A, E, I, 0, U, Y), based upon what wo^believe to bo the 
most comprehensive yet simplest summation of climatic factors, namely 
the FROST FREE PERIOD. 
Source 
A 
Sea level 
to 100 meters 
More than 210 days 
E 
100 to 
300 ” 
180 to 210 days 
sr 
I 
300 to 
600 " 
150 to 180 " 
!l 
0 
600 to 
900 " 
110 to 150 ” 
It 
U 
900 to 
1500 " 
60 to 110 ” 
it 
Y 
1500 to 
2000 " 
less than 60 days 
ti 
In general these source sites will bo found within the indicated 
altitude ranges. 
