ASPEN IN THE CENTRAL ROCKY MOUNTAIN REGION 35 
one of the lightest of woods when dry, green aspen is as heavy as dry 
oak or hickory. 
The costs of logging run approximately as follows, on a linear foot 
basis (mine props) : 
Cost of logging per thousand linear feet : 
Stumpage $5.00 
Cutting and peeling o. 33 
Skidding 1.67 
Hauling l 10.00 
Loading on cars 1. 50 
Total cost 21.50 
Selling price 27.50 
On a cord basis, including mostly trees too large for props, the 
cost is: 
Stumpage $0. 75 
Cutting .90 
Skidding .30 
Hauling 3.00 
Loading .20 
Total 1 5.15 
These figures apply to stands of aspen readily accessible from roads, 
not more than 12 miles from a railroad point. Merchantable stands 
are generally located in places easily logged, with little underbrush 
and easy slopes. 
MANAGEMENT OF ASPEN, SILVICULTURAL SYSTEMS 
The characteristics of aspen point unmistakably to a clear-cutting 
system. Thrifty stands are positively dependent upon clear cutting. 
(PL X, fig. 1.) Thinnings in merchantable stands are not to be con- 
sidered advisable as improvements to the stand, but they may be 
encouraged as a matter of economy, since they mean the utilization 
of the inferior material before it dies of suppression. Scattered 
cuttings have the effect of a selection system, and the removal of this 
selected material may well be detrimental to the remaining stand, 
since we have seen that reproduction that comes under partial shade 
is weak, develops slowly, and is likely to be crooked and knotty and 
to decay early. (PI. X, fig. 2.) For these reasons sales that will 
afford the utilization of the widest number of diameter classes are to 
be preferred, and sales of different classes ought to be concentrated 
in the same areas. 
Brush disposal is not a serious question in aspen stands, for it has 
little bearing on reproduction and the fire hazard is practically 
negligible. With moderate lopping the brush disappears in about 
four years. Special methods of brush disposal, calculated to inter- 
fere with the free grazing of cut-over areas by sheep, have been 
advocated for the safeguarding of reproduction. Their worth is not 
proved, however; and for the present, where regeneration is desired, 
administrative restriction of sheep grazing and of cattle grazing to 
some extent is the better method on clean-cut areas or in places where 
very old stands are going to pieces naturally. 
The rotations upon which aspen is to be managed will depend upon 
the site, the class of material desired, and the period during which 
