28 THE LOG OF A TIMBER CRUISER 
us who were new to.the work. We could scarcely 
have undertaken to cruise without it. 
And indeed, even experienced timber workers find 
it necessary to get some such line on how the trees 
run, in feet board measure, when they enter an un- 
worked region. In the Black Range the frequent 
taking of sample plots was particularly necessary 
on account of the constant variation in altitude and 
the consequent change of species and quality and 
amount of timber. 
In general the best stands of Western Yellow Pine, 
which is the chief, or technically the ‘‘dominant”’ 
species of the forests of the Southwest, are usually 
found at between 7,000 and 8,500 feet altitude, 
though scattering trees grow in the canyons as low 
as 6,000 feet and on slopes with a southern exposure 
as high as 10,000 feet above sea level. But at these 
higher levels, generally between 8,500 and 9,500 feet, 
the dominant type is a composite of Douglas Fir and 
Western Yellow Pine.’ Along creeks and on north 
slopes one is apt to discover that Douglas Fir and 
White Fir have crowded out the pine entirely, and 
compose practically the whole stand in such places. 
At 9,000 feet Engelmann Spruce appears, and above 
9,500 feet this species predominates, with perhaps 
a smaller stand of Alpine or Cork Bark Fir present 
as a secondary species. 
ince our work in the Black Range took us during 
the season through altitudes varying from 6,000 to 
over 10,000 feet we encountered at one time or an- 
