THE NATIONAL FORESTS OP IDAHO 17 



fires. Records kept during the past eight years indicate that now 

 only about half the fires are caused by lightning and that the re- 

 mainder are due to the activities and carelessness of man. 



Both the climate and the forest conditions prevailing are such as 

 to make the fire danger, particularly in northern Idaho, very great. 

 There is regularly a long period of drought in the summer season, 

 during which the dead timber and duff of the forest floor become 

 extremely dry. Strong winds are also common at this season of the 

 year. Perhaps the most dangerous factor, however, is the unusu- 

 ally low humidity. The summer is also the season of severe light- 

 ning storms. During many of these storms, known locally as " dry 

 storms," electricity discharges to the ground with great frequency. 

 For example, on July 1, 1924, a single lightning storm set over 100 

 fires in the Clearwater Forest alone, and many other storms have 

 almost equaled this record. The prevailing winds are westerly, and 

 in bad fire years the smoke haze, drifting in from the fires in the 

 valleys and mountains at a distance, as well as that which is pro- 

 duced by local fires, becomes so dense that lookouts are unable to dis- 

 cern the smoke of new fires starting up. 



There is often a great accumulation of dead and down material 

 underneath the dense forests, as well as a heavy cover of brush and 

 weeds of various kinds, adding both to the fuel which feeds the fire 

 and to the difficulty of fire-line construction. In fact, all the con- 

 ditions which increase fire danger seem to combine in the forests of 

 this region. 



Probably the most disastrous fires since the forests of Idaho were 

 placed under the protection of the Forest Service occurred in 1910. 

 A number of forest fires had been burning for days in northern 

 Idaho and western Montana. Hundreds of fire fighters were in the 

 hills trying to check the spread of flames. The curtain of smoke 

 became so dense that lookouts were almost entirely useless. On the 

 evening of August 20 the wind sprang up and rapidly grew to the 

 velocity of a hurricane. The fires broke all bounds. Flaming 

 brands were picked up and carried from crest to crest of the ridges, 

 dropping on the slopes and in the canyon bottoms between. Human 

 effort bacame entirely unavailing. The problem of the fire fighters 

 became one of self-preservation. In spite of all efforts and many 

 deeds of heroism 80 lives were lost. Scores of hairbreadth and al- 

 most miraculous escapes were recorded. The mining city of Wal- 

 lace, situated in a canyon, was set ablaze by falling brands, and alt 

 the outlying portions as well as part of the business section of the 

 town were destroyed. Small mining towns, lumber camps, and 

 homesteads were wiped out. Some of the fires ran together, in one 

 case making practically a solid burn extending more than 100 miles 

 east and west. Altogether, over 2% million acres of forest, some of 

 it of the finest western white-pine type, were destroyed. 



In 1919 another unusually dry season came on, and in spite of 

 the hundreds of men employed, 1% million acres in northern Idaho 

 and western Montana were burned over and timber worth millions 

 of dollars was destroyed. The cost of fire fighting alone was 

 $2,800,000. In 1922 another serious situation arose, and heavy 

 losses occurred. Three times in 1924 conditions in northern Idaho 

 again became critical. 



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