8 WESTERN YELLOW PINE IN ARIZONA AND NEW MEXICO. 
logs to the thousand. During an inspection trip of six weeks over — 
the Datil National Forest the largest yellow pine observed was 100 
feet high and 50 inches in diameter, estimated to saw 3,420 board 
feet. A single bole on the Coconino National Forest scaled 4,300 
board feet, while abnormal forked trees have scaled as high as 5,000 
board feet. There are few yellow pines on the Forests of the South- 
west over 120 feet in height, the highest so far observed being 129 
feet. Trees more than 46 inches in diameter are also rare, the largest 
diameters recorded being 58 and 60 inches, on the Coconino and 
Manzano National Forests, respectively. Average sections are esti- 

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WIA, \NESTERN YELLOW PINE 
PINUS PONDEROSA 
Fic. 1.—Distribution of western yellow pine within National Forests of Arizona and 
New Mexico. 
mated at from 3 to 3.5 sixteen-foot logs to the tree, a number of others 
at from 4 to 4.5, while on the Sitgreaves Forest a few individual trees 
have been estimated at 7 logs. On a sale on the Coconino Forest, in 
a typical stand, 926 blackjacks averaged 19.2 inches in diameter, — 
36.9 feet used length, and 218 board feet merchantable volume. On | 
the same area 1,863 yellow pines averaged 23.6 inches in diameter, 
52.4 feet used length, and 522 board feet merchantable volume. 
The blackjack form develops into the yellow-pine form when the 
tree is from 125 to 150 years old. Typical stands of overmature 
timber vary in age from 250 to 350 years, and the trees composing 



