20 BULLETIN 604, U. S. DEPARTMENT OF AGRICULTURE. 
not uncommon, therefore, to find reproduction occurring in even- 
aged stands separated by an interval of several years from trees older 
and younger. 
RANGE. 
GEOGEAPHICAL. 
Incense cedar, next to western yellow pine, adapts itself to a wider 
variety of conditions than any other tree native to California. It is 
found growing under almost every condition, and apparently is lim- 
ited in distribution only by extreme drought, excessive humidity, and 
the conditions prevailing at high elevations. Its range is from north- 
ern Oregon to northern Mexico and from the eastern border of the 
fog belt in northern California nearly to the limits of commercial 
tree growth in western Nevada. Its northern limits are irregular, 
reaching as far north as Breitenbush Creek, on the west side of the 
Cascades, and to the foothills surrounding Mount Hood on the east 
side. It also is found on the Eogue-Umpqua divide in eastern Ore- 
gon, whence it extends south throughout the Siskiyous into northern 
California. In California it ranges between the foothills and the 
subalpine zones on both sides of the Sierras to the Kern River 
Valley and throughout the coast ranges at increasing elevations into 
northern Mexico and Lower California, where it finally disappears. 
AXTITUDINAL. 
East of the Cascades in northern Oregon the tree is found between 
altitudes of 2,000 and 3,000 feet, and in the southern part of the 
State between about 4,000 and 5,000 feet; on the west side of the 
Cascades it is abundant between 1,500 and 3,000 feet, and even higher 
in the warmer situations. In the coast ranges of California it occa- 
sionally goes as low as 1,100 feet, owing to heavier precipitation and 
an abundance of atmospheric moisture; but the bulk of it is found 
between 3,000 and 5,000 feet. In the mountains of northern Cali- 
fornia it grows between 2,500 and 6,000 feet, occasionally reaching 
as low as 1,000 feet where conditions are particularly favorable. It 
attains its best growth, however, between 3,000 and 6,000 feet. In 
the southern Sierras it is seldom found below 3,500 feet, and extends 
up to 7,000 or 7,500 feet, doing best between 4,000 and 6.800 feet. 
On the east slope, in extreme eastern California and western 
Nevada, its range is limited to the Warner Mountains and the 
northern and central Sierras, where it is confined between the 5,000 
and 7,000 foot elevations. In the coast ranges of southern California 
and northern Mexico it grows still higher, the extreme aridity fixing 
its lower limit at about 4,000 feet and forcing it up as high as 9,000 
or 9,500 feet at its southern limits. 
