ATLAS OF UNITED STATES TREES 
Volume 6. Supplement 
INTRODUCTION 
Volume 6, Supplement, contains additional information to aid use 
of the five volumes of maps of the native trees of continental United 
States. New small maps of the eastern species of Crataegus, 
hawthorn, fill an omission of Volumes 4 and 5. A list of the 53 general 
and base maps is included. Finally, the indexes of common names 
and scientific names contain all species maps in Volumes 1-6. 
This Supplement brings to a close the project of preparing a distri- 
bution map for each native species in continental United States. The 
history of tree distribution maps has been reviewed in the introduc- 
tions of previous volumes and in an earlier article (Little 1951).! 
George B. Sudworth (1864-1927) was the dendrologist, or tree identi- 
fication specialist, in charge of the dendrology project of the Division 
(later Bureau) of Forestry and the Forest Service, U.S. Department of 
Agriculture, from 1886 until his death nearly 41 years later. 
Soon after establishment of the Forest Service in 1905, Sudworth 
(1913) undertook this mapping project but published only the first 
part: ‘‘Forest atlas. Geographic distribution of North American trees. 
Part I. Pines,’’ a folio volume with large maps of the 36 native 
species of the genus Pinus. It is unfortunate that the entire atlas was 
not published soon afterwards, when the maps for each species repre- 
sented current knowledge. Some smaller maps of conifers, poplars, 
tree willows, and walnuts of the Rocky Mountain regions appeared in 
5 later bulletins by Sudworth, the last completed after Sudworth’s 
death by William A. Dayton. However, most of the maps remained 
unpublished after Sudworth’s death, and no successor was appointed. 
Some years later, Munns (1938) published distribution maps of 170 
important forest tree species of the United States, based largely upon 
data collected by Sudworth. 
The present compiler has continued and expanded the mapping 
project to complete this 6-volume Atlas. He began research work with 
the Forest Service in 1934 and was the dendrologist in Washington, 
D.C., from 1942 until his retirement in 1975. A few months later he 
returned for a year under a temporary appointment and continued as 
a volunteer through 1978. 
This 6-volume Atlas was preceded by a Yearbook of Agriculture ar- 
ticle with 165 small maps (Little 1949, also reprinted separately in 
1950), by ‘‘Silvics of Forest Trees of the United States’’ (Fowells 
1965) with 124 maps by Little, and by ‘‘Geographic Distribution of 
the Pines of the World”’ (Critchfield and Little 1966) with maps of 18 
additional native species of pines. 
For assistance in preparing and drafting the maps of the Supple- 
ment, credit is due Barbara H. Honkala, research botanist, who also 
made the cover design. 
The 5 volumes with explanatory titles are cited in full under 
Selected References (Little 1971, 1976, 1977, 1978a; Viereck and Lit- 
tle 1975). They are United States Department of Agriculture Miscel- 
laneous Publications Nos. 1146, 1293, 1314, 1342, and 1361. Volume 6, 
Supplement is 1410. All have been printed by the United States Gov- 
ernment Printing Office, Washington, D.C., and are for sale by the 
Superintendent of Documents, U.S. Government Printing Office, 
Washington, D.C. 20402. 
Each volume contains an introduction. Subjects discussed include 
history of tree distribution maps, preparation of the maps, explana- 
tion of the maps, tree names, notes on ranges, rare and local species, 
applications of the maps, and selected references. Also, each volume 
has indexes of scientific names and common names and a list of 
maps under Contents. 
Several other Forest Service publications devoted to tree species 
distribution maps should be mentioned. The Forest Survey published 
maps of commercial forest trees in four Southeastern States: Missis- 
sippi (Sternitzke and Duerr 1950), North Carolina and South Carolina 
(Roberts and Cruikshank 1941a, 1941b), and Virginia (Evans 1942). 
‘The Distribution of Forest Trees in California,’ by James R. Grif- 
fin and William B. Critchfield (1972, revised 1976), has detailed 
maps of 86 species in that State. ‘Important Forest Trees of the 
United States’’ (Little 1978b) contains maps of 180 species. These 
maps are reductions of those in the Atlas. 
Many other publications containing distribution maps of native 
trees of continental United States have been cited elsewhere (Little 
and Honkala 1976; Little 1979). These include taxonomic mono- 
graphs, State tree handbooks, and State floras. 
' Names and dates in parentheses refer to Selected References, p. 5. 
