4 



26 



+ 



At Twin Lakes the timber begins at about 9,500 feet. In tlie San Luis 

 Valley it is much lower, about 6,500 feet above the sea. Here, however, 

 the lowland coniferous growth is made up entirely of Pinus monopliyl- 

 lus * and Jimipertis Virginiana. 



It seems that where the hills begin fairly, they hare been seized at 

 once by some tree. Cottonwood-trees appear both on the plains and 

 mountains, where the supply of water is constant or nearly so. The 

 conifers above named are constantly found associated on the foot-hills 

 at least as far north as Canon City. They do not fairly enter South 

 Park. The line along the valley of the Arkansas is sharply drawn. 

 The ridge dividing it from Trout Creek is covered on its western slope 

 by these trees, while to the east of it they hardly appear. 



From some facts observed, 1 am led to think that at no distant past 

 the growth of Coniferw extended much lower into the park than it now 

 does. I have seen the decaying remains almost down to the Platte. 

 The knots, which, as is well known, last a long time, were found scattered 

 here and there frequently in the lower portions of the open ground. 

 An occasional isolated clump of these trees still survives, far removed 

 from their associates on the mountain-sides; and at times one may 

 observe that the prolongations of pine-woods, which extend out into 

 the Park, become less and less dense, until finally only a single tree 

 remains at iutevals, these disappearing, and then only the half-decayed 

 remains reach farther out toward the valley. In one place it was ob- 

 served that the tops of these dead trees all pointed to the east. This 

 suggested the idea that the destruction may have been due to one of 

 the fierce west winds, which, during the fall-mouths, are so prevalent in 

 South Park. Once destroyed, other vegetation might readily crowd 

 the young trees out. A notable example of this was seen in one portion 

 of the foot-hills, where a whole forest of Finns monophyllus lay prostrate, 

 with not a single young tree coming on. As bearing upon this question 

 ot recession of the Coniferw toward higher ground, I may also remark 

 that where these tongues of timber ran down toward the center of the 

 Park, the oldest trees are Coniferw and the younger growth is of cotton- 

 wood. This IS especially marked at the lowest limit of the trees. Per- 

 haps mere " rotation of crop" may serve to explain the change. 



ihe timber-belt ends at about the greatest center of development of 

 the nutritious bunch-grasses, though these do extend in magnificent 

 growth up into the open valleys and among the less dense timber to an 

 altitude of nearly 11,000 feet. 



From South Park to the Kew Mexican line we regularly found abun- 

 dance ot this forage on the eastern slope of the main chains. In the beau- 

 titul valley ot the Conejos Eiver, after striking the timbered region, we 

 tound luxunant bunch-grass covering the ground as thickly as it could 

 stand. In November it was still green about the roots, and w^as eagerly 

 eaten by our starved mules. Finns ponderosa formed open clumps, and 

 under protection of these trees it attained what seemed to be its Aiasi- 

 mum growth. 



Frorn 9,500 to 10,500 feet the principal arboreous growth was made 

 up of Finus- contorta. Firms ponderosa, Abies Menziesii, Abies alba, and 

 Abies bal^msQ^ Abws Donglasii seemed more arUTme at a smne'what 

 less e evation. Fmus ponderosa was frequently seen to extend in full 

 size almost to the verge of the timber-line, and often to attain its largest 

 growth at an elevation of 11,000 feet. 



*«sni/'.?''t .tf^*?* *^1 determination of Mr. Josiuh Hoopes, whp Las given this order 

 Engelm. ''^*''''*''*"' ^^''"Sli other botanists call the tree in question Pinus edalU, 



