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REGION 
Appendix 
ss 
Inventory Methods and Sources 
Volume Tables 
Several existing Douglas-fir volume tables had given 
satisfactory results for certain localities, but comparison with 
measurements of felled timber showed that they could not be 
used regionally. Accordingly, a form-class table was de- 
veloped and checked against measured volume of 1.6 million 
board feet of felled and bucked timber in different sections of 
the region. In nearly every instance this table checked with- 
in 0.5 percent of the actual measurements, and in no case did 
it deviate more than 2.6 percent. 
A western hemlock volume table was constructed in the 
same way, and was proved to be accurate. For western red- 
cedar a volume table made on the Quinault Indian Reserva- 
tion by Henry B. Steer, then of the United States Indian 
Service, was used. For Sitka spruce, table 80 of Volume 
Tables for the Important Timber Trees of the United 
States: Part I, Western Species (77), was accepted after ad- 
Table 79 from the 
same publication was adopted for silver fir and white fir, 
after it had been adjusted to a 12-inch top diameter and ex- 
tended to include trees as large as 70 inches in diameter. 
Table 77 in the publication just mentioned, prepared by 
R. H. Weidman in 1917, was accepted for noble fir. A table 
made by Henry B. Steer on the Quinault Indian Reservation 
was used for western white pine. 
structed for ponderosa pine. 
red alder was prepared on the basis of an existing table (70) 
made by Griffin and Wilcox. 
wood table (table 11) in Volume Tables for the Important 
Timber Trees of the United States: Part III, Eastern Hard- 
woods, was found to be suitable for other hardwoods. 
justment to a 12-inch top diameter. 
A form-class table was con- 
A table for use in estimating 
The second-growth cotton- 
Organization of Field Work 
More than 40 percent of the region’s total forest-land area 
This portion, 84 
percent of which is in Federal ownership, includes the most 
is within the boundaries of national forests. 
mountainous, rugged, and inaccessible lands of the region. 
When this work was started, national forests either wholly or 
chiefly within the Douglas-fir region numbered 12; since 
146 
2 
then, without any significant change in total area, the num- 
ber has been reduced by consolidations to 10. These na- 
tional forests now range in gross area from about 700,000 
to 1,850,000 acres each, averaging approximately 1,200,000 
acres. 
A greater part of the national-forest lands than of the 
The 
procedure followed on them was influenced not only by 
the ruggedness of the many mountain areas but also by 
other lands had to be covered by field examination. 
It was 
decided that the work on national-forest areas that had not 
scarcity of roads and shortness of field season. 
been intensively cruised should be an intensive reconnais- 
sance. Men familiar with the national forests of the region 
were selected from the local forest organizations to do this 
work. 
For lands outside the national forests a permanent organi- 
zation of 5 type mappers and 3 check cruisers was formed. 
This was augmented by field assistants during the field 
season and computers during the winter months. In peak 
periods as many as 40 or 50 men were employed on the 
survey of these lands. 
Collection of Existing Information 
The sources of information already in existence for na- 
tional-forest areas included intensive timber cruises cover- 
ing about 15 percent of their total; records of an extensive 
reconnaissance made in 1909-10 and amended in 1922, of 
examinations of cut-over land, of planting reconnaissance 
work, of land-exchange examinations, of appraisals, of 
settlement cases, of trespass cases, and of fire damage; aerial 
and panoramic photographs; 
Of the land outside national forests about 30 per- 
cent had been covered by intensive cruises. 
and miscellaneous other 
records 
Collecting 
information on areas outside national forests involved in- 
vestigation of the records of all counties and consultations 
with lumbermen, public officials, foresters and engineers in 
ptivate employ, and many other persons. The principal 
sources of information found were private timber cruises in 
the hands of timber owners or their agents, county cruises 
made for taxation purposes, and cruises of State-owned 
lands, Oregon & California Railroad revested grant lands, 
and Indian reservations. In cases in which county cruises 
were sufficiently complete and appeared to be reliable 
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