

101 
most of the building lumber, both common and finishing. In favoravle 
situations the trees of this species attain a height of 100 feet and the 
trunks a diameter of 6 or 7 feet. 
The White Pine is of smaller growth than the Yellow, the wood is 
softer and more subject to decay. The two kinds are, however, used 
for many Similar purposes. 7 
Lodge-pole Pine seems to be a stunted variety of Pinus Murrayana. 
It is a slender tree which covers rarge areas upon the mountains. It 
grows to a height varying from 20 to 100 feet, witu trunks from 2 to 10 
inches in diameter, often forming masses so nearly impenetrable that 
trails must be made with the ax. <A section from the trunk of one cf 
these trees measures 24 inches in diameter and has fourteen layers of 
annual growth. A lumberman of experience states that good saw-tim- 
ber can be had from the same kind of pine where tlie growth is less 
dense and crowded. The smallest kinds are extensively used for fenc- 
ing, logging” for mines, and by the Indians in the construction of 
their lodges. <A similar growth is foxnd in portions of Wyoming and 
Colorado. 
Cottonwood and Box-Elder border the streams at comparatively low 
elevations. The Aspen covers large surfaces which have been denuded 
of the original forest growth. It prefers northern slopes and narrow 
moist valleys. . ° 
Although the forest area of the Territory is large, it is being rapidly 
reduced. The destruction by forest fires is almost beyond computation ; 
railroads use and transport immense quantities of timber; lumbering 
operations cause a large and steady drain upon the forests; while the 
consumption of timber for mining purposes is of equal magnitude. 
The Territorial laws prescribe penalties for the willful! or careless set- 
ting of fires, or failure to extinguish them; and county commissioners 
are required to post notices annually in conspicuous places, calling atten- 
tion to the provisions of the law. Notwithstanding these precautions, 
forest fires are frequent and destructive in the extreme. 
A recent legislative act provides for rebatements in taxation to per- 
sons planting and cultivating forest trees, under certain conditions 
named in the law. 
Irrigation is practicable at different points upon all streams near the 
mountains, and it is stated that by this means crops are cultivated in 
every county of the Territory. 
East of Great Falls the Missouri River has cut a channel 600 to 900° 
feet deep, through the table-lands to the Dakota line. This gives toits 
tributaries a very swift current, although their channels are quite deeply 
sunken below the adjacent plains. In the Yellowstone system the 
waters flow somewhat nearer the general level. 
A number of great irrigation enterprises have been undertaken. The 
eanal of the Minnesota and Montana Land and Improvement Company, 
_ in Yellowstone County, is about 40 miles long by 35 feet wide, and 5 

