THE NATIONAL FORESTS OF COLORADO 35 



by its conflict with mountain storms; for this is the tree frontiers- 

 man of the Koeky Mountains, jealously guarding the timber-line 

 march. The fantastic form of these witch trees has made them the 

 quest of many artists and mountain climbers. But more important 

 is the value of these trees in preventing too rapid melting of the 

 spring snows and in protecting the soil on these steep slopes against 

 erosion. A little lower down in the protected valleys and canyons 

 the trees grow tall and straight and are valuable for the production 

 of lumber and other products. Alpine fir is commonly found in 

 these stands. Trees in this Engelmann spruce type are conspicu- 

 ously lacking in uniformity of size. There is usually a great deal 

 of underbrush, too, so that the type generally has the appearance 

 of a luxuriant tangle, very different from the open, clean stands of 

 western yellow pine or even the lodgepole pine below. Douglas fir 

 grows in mixtures over a wide intermediate range and is very valu- 

 able for the making of construction timbers and railroad ties. 

 Lodgepole pine is common in the northern forests of the State, and 

 is easily recognized by its neat stands of uniform, crowded, tall, 

 slender, even-aged trees. 



Altogether 12 species of evergreen trees are found in the central 

 Bocky Mountains. Engelmann spruce, alpine fir, western yellow 

 pine, Douglas fir, lodgepole pine, juniper, limber pine, and pinion 

 are the most important commercially. Blue spruce, bristlecone pine, 

 white or silver fir, and the low or scrub juniper, the other coniferous 

 species native to the State, are of less importance commercially. 



There are no broad-leaf trees of commercial importance, except the 

 aspen, or " quaking asp," which is used in the manufacture of ex- 

 celsior and boxes. In addition, this tree, with its light-colored, shiny, 

 trembling leaves and nearly white bark, adds much beauty to the 

 mountain scenery, and is of great importance in the forest because 

 of the readiness with which it, like lodgepole pine, reclaims areas 

 devastated by fire. All of the other broad-leaved trees come only 

 to the foot of the mountains and are restricted to the canyons. 



The evergreens all belong to one great family, which is sometimes 

 called the " pine family," and which, as shown by fossils, has been 

 in existence since the earliest geological age. Hence, it is not a 

 serious error to call all the evergreens "pines," but it is best to call 

 them conifers, because the habit of bearing the seeds in cones is 

 characteristic of them all. Even the berry of the juniper is a " cone," 

 its segments in most species being completely grown together. 



The western yellow pine (Firms ponderosa) can be distinguished 

 from any other in the region by the fact that its needles are 4 to 6 

 inches long and occur in bunches of two or three. The needles are 

 coarse, and the limbs are often large, giving the trees a rather heavy 

 appearance. The cones open late in the fall, permitting the seeds 

 to drop out, so that the cones found on the ground are invariably 

 empty. But by pressing on one of the segments or " scales " of the 

 cone one can easily see two large pits where the seed rested until 

 ripe. This tree grows mostly in the lower part of the mountains, 

 where the temperature is warmer. It is seldom seen except on the 

 warm south slopes. 



The "versatile" limber pine (Pinus flexilis) is able to grow under' 

 so many .conditions because of the large size of the seed and the 



