UNITED STATES DEPARTMENT OF AGRICULTURE 
MISCELLANEOUS PUBLICATION NO. 287 
Washington, D. C. 
March 1938 
THE DISTRIBUTION OF IMPORTANT FOREST TREES OF THE 
UNITED STATES 
By E. N. Muwnns, Chief, Division of Forest Influences,! Forest Service 
INTRODUCTION 
Information on the range and distribution of 
forest trees has far-reaching practical usefulness 
in addition to its value to botanists, naturalists, 
teachers, and others whose work or interests 
are with trees. It is a valuable tool for the 
forester, the lumberman, and the manufacturer 
in search of raw materials. It is an essential 
element in erosion and flood control operations, 
and in land-use planning. Indeed, present 
trends toward better planning and integration 
of land use are directing increased attention to 
forest cover, the species represented in it, and 
the possibilities of enlarging the contribution of 
forest land to community welfare. In some 
cases the occurrence of certain species in a region 
may assume major importance in such planning. 
It is the purpose of this publication to make 
readily accessible the information available in 
the Forest Service on the distribution of 1m- 
portant forest trees. 
The Forest Service, for over 30 years, has 
been actively gathering data on the species of 
trees present in the United States and the extent 
of their occurrence. More than 20 years ago 
distribution maps were published for American 
pines, and as a result much new information on 
these and other forest-tree species has been ob- 
tained. Much of this information has been pre- 
sented in condensed form in United States De- 
partment of Agriculture Miscellaneous Circular 
92, Check List of the Forest Trees of the United 
States, Their Names and Ranges. There has 
1 The maps here presented have been based very largely upon data collected by the 
late George B. Sudworth, dendrologist of the Forest Service until his death in 1927. 
Since his death this work has been carried on as an activity of the Division of Silvics. 
Many of the more recent data have been compiled by William W. Mitchell, junior 
forester. 
2399—38——1 
been a strong demand, however, to have this 
material available on maps because of the greater 
accuracy, simplicity, and detail possible in this 
form of presentation. Even the most detailed 
published descriptions of species distribution 
are found to be too broadly generalized when an 
attempt is made to plot the ranges on maps. A 
mere listing of known poimts of occurrence 
would be even less satisfactory. 
The maps do not, however, carry any implica- 
tion as to the density, continuity of occurrence, 
or commercial quality and quantity of the various 
species. Lumbering, fire, and agricultural de- 
velopment in many parts of the United States 
have markedly affected the origina] forest. 
Although in some instances they may have 
caused an extension of the range of some species, 
their influence is usually in the opposite direc- 
tion, and in extreme cases, such as in portions 
of the Lake States and the South, they have 
eliminated formerly abundant species from fairly 
large areas. It is, however, impractical to show 
such locally depleted areas on maps of the scale 
used. 
No attempt has been made to show the com- 
mercial range of important timber tree species, 
since changing demands, practices, and stand- 
ards in utilization would make such information 
out of date in a comparatively short time. 
So many sources of information, published 
and unpublished, have been drawn upon in the 
preparation of the maps that individual refer- 
ence and acknowledgment is not feasible. 
The sources include taxonomic and botanical 
handbooks, ecological papers, and occurrence 
(1) 
