INSECT ENEMIES OF THE PINE IN THE BLACK HILLS 
FOREST RESERVE. 
REQUEST, AUTHORIZATION, AND INSTRUCTIONS. 
The work herein reported was undertaken by request of Mr. Gifford 
Pinchot, Chief of the Bureau of Forestry, under authorization from 
the honorable Secretary of Agriculture and instructions from Dr. L. O. 
Howard, Chief of the Division of Entomology. 
THE INVESTIGATING TRIP. 
The investigations were conducted, in company with Mr. Pinchot 
and his chief field assistant, Mr. Griffith, on September 1 to 4, 1901, 
along a route traversed through the reserve from Spearfish, via Iron 
Creek, Bear Gulch, and Cement Ridge, South Dakota, Rifle Pit, 
Wyoming, and Spearfish Creek, to Lead, 5. Dak. 
THE CONDITIONS OBSERVED. 
Vast numbers of rock pine (Pinus ponderosa scopulorum) that were 
dying, or had died within recent years, of sizes ranging in diameter 
from 4 inches to the largest trees, were observed along the route. 
The dying trees occur in clumps of from afew examples to many 
hundreds, and in some sections, as viewed from the summit of Cement 
Ridge and other favorable points, the dying, recently dead, and old 
dead trees cover large areas. 
« 
THE AMOUNT OF DEAD TIMBER. 
Mr. H. 8. Graves* estimated in 1897 that about 3,000 acres of pine 
in the Black Hills Forest Reserve had been killed. Furtaer data fur- 
nished by the Bureau of Forestry show that the actual amount of dead 
timber, as determined by Mr. Griffith and party in a detailed survey of 
the timber resources of the reserve in 1901, is, ‘*An average stand of 
1,956 feet board measure of bug-killed timber on 116,000 acres, giving 
a total of 226,890,000 feet board measure.” 
HISTORICAL REFERENCES. 
It is the general opinion among settlers and others who have had an 
opportunity to note the conditions affecting the pine that the dying 
timber commenced to attract attention about six or seven years ago, 
or about 1895. 
“Nineteenth Annual Report U. 8. Geological Survey, 1897-98, Part V, p. 87. 
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