HETCH HETCHY TIMBER AFFECTED 



SPECIAL investigations by the 

 experts of the Department of 

 Agriculture have shown that as 

 much as 95 per cent of the 

 timber in some of the canyons and val- 

 leys of the Toulumne River, which is to 

 supply the water for the Hetch Hetchy 

 project, has been killed by bark-boring 

 insects. 



The areas in which practically all of 

 the timber has been killed, some of it 

 many years ago, are Jack Main Canyon 

 and Matterhom Cznyon. It was found 

 that the forest growth of the entire 

 watershed was more or less affected, 

 and that the dustructive insects were 

 killing a great amount of timber from 

 near Tenaya Lake through the forests 

 surrounding Toulumne Meadows to and 

 through Virginia Canyon. 



This alarming condition, affecting as 

 it did the scenic beauty of the area 

 north of the Yosemite Valley and its 

 consequent effect on the water supply 

 and general economy of the Hetch 

 Hetchy project, presented a problem of 

 great importance. 



As soon as the matter was called to 

 the attention of the Secretary of the 

 Interior in the fall of 1912, he appealed 

 to the Secretary of Agriculture for such 

 advice and assistance as his Department 

 could render through the expert who 

 has charge of the forest insect branch of 

 the Bureau of Entamology. 



The matter received the required 

 prompt attention and arrangements 

 were soon made for active warfare 

 against the depredating beetle. A plan 

 of procedure was outlined by the 

 expert and recommended by the Secre- 

 tary of Agriculture to the Secretary of 

 the Interior. According to the plan, 

 the Interior Department was to allot 

 the required funds, the control work to 

 be carried on under the immediate 

 supervision of an entomological assist- 

 ant of the Bureau of Entomology. This 

 plan was adopted and the work was 

 started just as soon as the weather con- 

 ditions permitted in June, 1913. 



The areas near Tenaya Lake and in 



150 



the Cathedral Basin around Toulimme 

 Peak to the Toulumne Meadows were 

 carefiilly cruised for the location and 

 marking of the particular trees, in the 

 bark of which the broods of the destruc- 

 tive beetle had passed the winter. Two 

 areas representing centers of infesta- 

 tion were thus located and designated 

 — one as the Tenaya Project, the other 

 as the Cathedral Project. 



Control work was started on the 

 Tenaya Project on ]\Ay 1, and finished 

 when the beetles began to emerge from 

 the bark on Jtily 24th. Work on the 

 Cathedral Project was started on Sep- 

 tember 8th, after the beetles coming 

 from the overwinter broods had en- 

 tered the bark of the living trees, and 

 was completed on October 7 th. 



The method recommended and fol- 

 lowed was to fell the infested trees, lop 

 off the limbs, pile them on the prostrate 

 trunk, and set fire to it; thus the in- 

 fested bark was scorched or burned to 

 a sufficient extent to kill the broods of 

 the insects. The trees thus treated 

 ranged in diameter from 6 inches to 54 

 inches, with the average of about 22J^ 

 inches. 



One thousand, six himdred and sev- 

 enty-one trees were treated in the two 

 projects, at a cost of $1,158, including 

 all expenses except the salaries of two 

 representatives of the Biu^eau of Ento- 

 mology who directed and assisted in 

 the work. 



It is claimed that this work, with an 

 additional expenditure of about $500 

 next season, will be sufficient to bring 

 the beetle under such control that very 

 little attention will be required to pro- 

 tect the remaining living timber from 

 further serious injiuy. Both, this and 

 an infestation in the timber around the 

 rim of the Yosemite Valley will receive 

 the required attention next season. 

 The Interior Department has expressed 

 a determination to prosecute a warfare 

 against the depredations of insects in 

 the Yosemite and Glacier National 

 Parks to the limit of the funds available 

 for the purpose. 



