CHAEAOTEK AND VOLUME OF MBEOHANTABLE TIMBER. 23 



Except in perpetually moist and rich soil the growth of the trees is slow. Limber 

 pine requires one hundred and twenty to one hundred and fifty years to reach heights 

 of 30 to 40 feet, with breast-high diameters of 16 to 18 inches and clear trunks 12 to 

 15 feet in lengthi> Lodgepole pine in close-set stands averages 70 to 90 feet in length, 

 with breast-high diameters varying from 8 to 12 inches after one hundred to one 

 hundred and fifty years of growth. White-bark pine and other trees of the snbalpine 

 forest at high elevations are slow growing. To reach a breast-high diameter of from 

 10 to 16 inches, and a length of bole from 25 to 45 feet requires one hundred and 

 eighty to two hundred and fifty years. In similar situations Engelmann spruce 

 requires from one hundred to one hundred and twenty j'ears to attain equal dimen- 

 sions. In moist situations at low or middle elevations Engelmann spruce will reach 

 heights of 50 to 60 feet, with breast-high diameters varying from 16 to 24 inches in 

 one hundred and twenty to one hundred and forty years. The red fir is likewise a 

 slow growing tree, owing to its habitat on dry and rocky soils. It requires from one 

 hundred and twenty to one hundred and fifty years to attain breast-high diameters of 

 12 to 18 inches, with lengths of bole varying from 60 to 80 feet. With the exception 

 of the lodgepole pine very little timber in the reserve develops any considerable 

 length of clear trunk. Limby and knobby boles with rapid taper and large crowns 

 are the common characteristics. The lodgepole pine, set in close-stocked stands from 

 the first, generally develops long, symmetrical, columnar trunks, although it rarely 

 has a large diameter. 



CHARACTER AND VOLUME OF MERCHANTABLE TIMBER. 



The timber in the reserve, valuable for commercial purposes, may be divided 

 into two classes: (1) Timber of sufficient dimensions and quality to furnish saw 

 logs, and (2) timber fit only for fuel, fencing, pole, railroad ties, and mine props. 

 The mill timber is present in much the smaller proportion, owing to the prepon- 

 derance of the lodgepole pine, with its slender, pole-like growth, and the generally 

 low, stocky stature of the other species of trees. 



More mill timber is obtained from the lodgepole pine than from any other 

 species, owing to its accessibility and abundance, and to its uniform distribution in 

 areas having the most favorable climatic and soil conditions. 



Next in volume comes Engelmann spruce. Although the total volume of the 

 species is less than one-half that of the lodgepole pine the volume of mill timber is 

 nearly 87 per cent of that of the pine, owing to the fact that the spruce of mill- timber 

 ■ dimensions is chiefly an old growth and its yield of saw logs is much greater propor- 

 tionally than that of the lodgepole pine. Inversely its yield of fuel and pole timber 

 is much less, amounting to only 33 per cent of that of the pine. The spruce is but little 

 used either for mill timber, fuel, or fencing material because the heaviest and best 

 stands of the species occur in localities remote from transportation or demand. 



