20 BULLETIN 1494, U. S. DEPT. OF AGRICULTURE 
or has been allowed to accumulate for a year or two. This difference, 
if it could be calculated, would be an offset to the cost of piling slash. 
Forest Service costs are also open to some objection as a basis for 
calculating costs on privately owned timberland, since many of the 
basic conditions are different from those on association areas. How- 
ever, since 1919 the Forest Service objectives have been similar to 
those here proposed, and the results shown in Table 4 will be in some 
measure indicative of what the expenses under the proposed plan 
may be. | 
TABLE 4.—Unit costs of fire control, and area burned; north Idaho national 
forests, 1920-1924 
Average annual cost per acre 
Average 
area 
burned 
: National forest 
Patro! 1 pugnres: Total | annually 
Cents Cents Cents Per cent 
"PICASSO ee VE CEE YW Ee ee SET Be es iy Rey. Pee 4.14 7. 28 11. 42 0. 53 
ARO TU GO ROMG Cag te ae Se Sa ee 2 es Te et eas op tenet sa een Bae ane 3: 43 3. 60 7. 03 5 7A} 
CocurdiAMlenettsi keris es ees ee Eee ek as ek eae 5. 43 2. 99 8. 42 .32 
POH Bh COTS NN ER ee i Tes Oeics eee oeepe Rha ewE ey aay Le RC Lt Selly 6. 45 4.79 11. 24 . 54 
Clear wale rete aeons SE ee es a eee ie dees owe aed ey MER ee 4.89 2. 53 7.42 a6) 
TNS GRE I Ag ee De ee 4, 86 3. 93 8.79 . 38 
1 including maintenance of improvements. 
SLASH DISPOSAL 
No factor in the fire problem of the white pine region is more 
important than the slash created by logging operations. A white 
pine slashing, particularly if there is a considerable amount of cedar 
in mixture, is nearly the most inflammable mass conceivable, short 
of an actual explosive. If this is burned as it lies, a method ordi- 
narily called “broadcast burning,” the inflammability of the area is 
reduced for one year. But after the first year inflammability in- 
creases rapidly because of the large quantity of material killed by the 
fire, consisting both of young growth and of unmerchantable trees 
left by the logging operation. ‘The dead trees soon come down in a 
tangled mass, and fireweed, thistle, and grass grow in the burned 
soil and become tinder-dry in August. 
Most of the slash from logging operations on private land in north 
Idaho has been burned broadcast, sometimes accidentally but usually 
intentionally, in an attempt to comply with the State fire law. Most 
fire wardens and foresters are now in agreement that broadcast 
burning is not a solution of the problem of disposing of slash. It 
is almost impossible to protect extensive burned areas, and as a 
result the same areas burn again. As some one has well expressed it, 
the old slash burns are the giant powder and the new slash the 
detonator to set it off. The last few years have seen a long series of 
such explosions. 
In the Coeur d’Alene district in Idaho during a five-year period 
over 90 per cent of the area burned over by forest fires outside of the 
Coeur d’Alene National Forest has been swept by fire starting in 
slashings or in cut-over areas where slash has been disposed of by 
broadcast burning. 
