 The Blackwater fire consumed 1 @,@ 700 acres ( 690 ha ) of old @-@ growth forest dominated by Douglas fir trees on the west slopes of Clayton Mountain . At the time the firestorm occurred , the temperatures were about 90 ° F ( 32 ° C ) and the relative humidity was only 6 percent . Though most of the firefighters consisted of Civilian Conservation Corps ( CCC ) employees , they were led by more experienced United States Forest Service ( USFS ) fire managers . Firefighters in the first half of the 20th century used mostly hand tools to suppress wildfires , and all gear was carried by the firefighters or by pack animals . Weather forecasting and radio communication were generally poor or nonexistent . 
