the full, modern capability of aerial photo in- 
terpretation as a tool in their day-to-day work. 
Despite the slow rate at which good aerial 
photography has become available to range 
managers, in the late 1930’s and early 1940’s 
they were among the first to use aerial photog- 
raphy in resource surveys. Range technicians 
quickly found that they could: (1) Do more 
consistent and accurate mapping of resource 
characteristics, (2) estimate parameters for 
sampling more precisely, and (3) perform nec- 
essary fieldwork more efficiently (Reid et al. 
1942, Clouston 1950). Aerial photography was 
found so superior to the grid-traverse, plani- 
metric, topographic, and formline mapping 
methods used in range surveys through the 
1930’s that small-scale Army Mapping Service 
photography was used where nothing better 
was available. Henriques (1949) has written of 
the advantages of controlled mosaics for range 
resource mapping and of the substantial use of 
aerial photos in regular range management 
within the Bureau of Land Management start- 
ing immediately after World War II. 
The Soil Conservation Service, U.S. Depart- 
ment of Agriculture, has used aerial photo- 
graphs to make range site and condition sur- 
veys since they became available to the Depart- 
ment in the mid-1930’s. The Soil Conservation 
Service also pioneered in the use of uncon- 
trolled photo mosaics at scales as large as 
1:15,840 in the cartographic presentation of 
range site and condition survey information 
and the details of the management program. 
Similarly, the Bureau of Indian Affairs, U.S. 
Department of the Interior, has used aerial 
photography to make some combined range 
and soil surveys on Indian lands. The Pacific 
Southwest Forest and Range Experiment Sta- 
tion, through the California Soil-Vegetation 
Survey Program, has advanced the use of aer- 
ial photo interpretation in the field mapping of 
both vegetation and soil features of range and 
forest areas. With very few exceptions, all of 
this work has been done with aerial photogra- 
phy taken for some purpose other than range 
resource analysis. 
Even though more than 90 percent of the ag- 
ricultural land had been photographed by the 
beginning of World War II, rangeland gener- 
ally was only photographed to block out flight- 
lines near cropland. It was not until the late 
1950’s that aerial photography, other than 
very small-scale Army Mapping Service pho- 
tos, became generally available for the western 
range. It may surprise some individuals to 
learn that first-time coverage is still being 
flown over important range areas at scales ac- 
ceptable for intensive range resource analysis 
and management (1:15,840 and 1:12,000). 
Largely because of variation in the quality 
of photographic prints and season of photogra- 
phy, range management people have done little 
to develop photo interpretation aids and keys 
that would permit the compilation of informa- 
tion by photo interpretation alone. Our litera- 
ture does not illustrate the kind of photo inter- 
pretation keys and aids that were worked out 
for the military during World War II and re- 
ported by Colwell in 1948, nor those for for- 
estry applications as reported by Steigerwaldt 
in 1950. These kinds of aids and skills are just 
now being developed for the range resources 
area by workers at the University of Califor- 
nia, Berkeley; at Oregon State University; and 
at the Rocky Mountain Forest and Range Ex- 
periment Station, Ft. Collins, Colo. (Carneggie 
et al. 1967; Culver and Poulton 1968). 
PREMISES, CONCEPTS, AND PRINCIPLES 
Few, if any, of the premises, concepts, and 
principles shown by our research to be impor- 
tant in range resource analysis are new. We 
claim originality only for the way they are ex- 
pressed and related to the job of resource anal- 
ysis (Culver and Poulton 1968). 
Cartographic Premises and Principles 
Nearly all Federal rangelands have been 
surveyed at least once since 1911, but many 
acres of State and private rangeland are still 
being inventoried for the first time. Whether 
the purpose of resource analysis is repeat sur- 
vey or first-time coverage, the maps, legends, 
and analysis must improve the position of the 
decisionmaker by (1) improving or strengthen- 
ing the ecological interpretations of the land- 
scape, or (2) providing a more detailed and ac- 
curate picture of the resource and its potential- 
ities to match the growing needs of more inten- 
sive management. 
In meeting these goals, it is quite common 
for range resource people to think in terms of 
the greater practicability of large, highly gen- 
eralized mapping units. It is not uncommon to 
encounter the view that detailed resource maps 
are impractical. 
[PRINCIPLE:] In the cartographic 
representation of landscapes, it is bet- 
ter to err by too refined mapping than 
too broad generalization—informa- 
tion presented should exceed today’s 
needs. 
If the analyst errs by exceeding the informa- 
tional needs of the manager, or if he presents a 
picture more intricate than is needed for some 
applications, it is a simple matter for the user 
to combine the information on an overlay or 
variously colored map if he is adequately in- 
formed about the resource analysis procedure. 
