AMOUNT OF DISEASED TIMBER. 31 



1899, July. Live trees attacked by the bark-boring beetles. 



1899, September. Wood of the lower part of the trunk starting to blue. 



1899, December. Wood blue to the heart below, and wood of the top partially 

 blue. 



1900, May. "Sorrel-top" stage; leaves turning yellow; wood wholly blued. 



1900, October. " Red-top" stage; leaves red and lower ones starting to fall off; 

 wood blue, but sound. 



1901, May. "Black-top" stage; leaves falling off and fallen wood starting to 

 decay; "red rot" in the tops. 



1901, October. "Black-top" stage; leaves all fallen; top badly decayed and in 

 many instances broken off. 



This calendar must be considered a tentative one, based upon obser- 

 vations of two years, although in the main it is probably correct. 

 The " red-rot " part is extremely variable, and can not be assigned to any 

 definite period. The time when the tops will begin to decay is depend- 

 ent upon the weather at any particular season, the amount of rain, the 

 vigor of the tree and the length of time it takes the tree to die com- 

 pletely after the beetles have attacked it, the position of the tree in 

 the forest, the prevailing winds, and probably other factors more or 

 less related to those mentioned. 



It is exceedingly important that this variability be recognized, for 

 its bearing on the cutting and utilization of the dead timber is of the 

 greatest importance. There may be ' ' black-top " trees which will be 

 sound from the ground to the very top, and these trees may have 

 stood in the forest for years in this condition. Not far awa} r one will 

 find others which have barely reached the "black-top" stage which may 

 show signs of decay to within a few feet of the ground. It is there- 

 fore entirely impossible to lay down a hard and fast rule, and to state 

 that the " black tops" after a year are all of no value as timber. 



The average conditions in the Black Hills are certainly very favor- 

 able for the development of "red rot," and one will probably not be 

 very far from the truth when he assumes that after the trees have 

 reached the ' ; black-top " stage they are liable to decay and deteriorate 

 within a comparatively short time; that time probably will not exceed 

 two years. 



AMOUNT OF DISEASED TIMBER. 



In the foregoing, but brief reference has been made to the actual 

 condition of the forests in South Dakota at this time and to the extent 

 of the injury following the attack of the bark beetles. The amount of 

 dead wood, both standing and fallen, is very large, and as the beetles 

 are still at work, it is steadily increasing. It is, of course, rather dif- 

 ficult to make estimates of the exact amount without an actual survey 

 of the whole region. A trip through the worst region i. e. , north of 

 Spearfish River and west of the Burlington Railroad tracks was made 

 during the past summer, in company with several expert timbermen, 



