ocrT., 1899.] WHITE-BARK PINE BELT. Al 
and a half across (horizontally), must contain thousands of acres of the 
dwarf, flattened pines. Along its lower edge, singularly enough, trees 
of the same species suddenly stand upright and grow to large size, 
forming a rather solid forest, perhaps 30 feet in height, with an abrupt 
front facing the dwarf pines above. The suddenness of the transition 
is unusual and difficult to explain. 
The forest just mentioned is probably the largest continuous area of 
Pinus albicaulis on Shasta, Situated a little below timberline, it 
stretches, apparently without interruption, from North Gate Buttes 
to Diller Canyon, a distance of fully 5 miles, thus encireling the north- 
west quadrant of the mountain, including Shastina. 
Perhaps the most attractive grove of white-bark pines on Shasta is 
one that fills an open gulch or glade on the east side of North Gate 
Buttes. Here, in the lower part of their belt, the trees are large and 
uncommonly symmetrical, and the gray pumice soil is covered with 
silvery lupines. In ascending the gulch the pines gradually decrease 
in size until at ‘The Gate’ (alt. 8,500 feet) they are dwarfed and their 
tops are broadly flattened. 
The normal altitudinal limits of the white-bark pines on Shasta are 
hard to fix. On the south and southwest sides the trees descend in 
places to 7,500 feet and range thence upward on the hottest ridges to 
an extreme limit of 9,800 feet. But this extreme altitude is attained at 
two points only—on the long ridge above ‘The [South] Gate’ (near Red 
Butte) and on a ridge about a quarter of a mile west of Mud Creek 
Canyon. On the west rim of the canyon the pines stop at 9,500 feet 
| 
Fic. 23.—A large prostrate tree of white-bark pine, a littl below timberline. 
and on the ridge on the east side at 8,600. Probably 9,300 to 9,500 
would be a fair average for their upper limit on the warmer southerly 
slopes. 
On the cold northeast slope, just south of Brewer Creek, they descend 
21753—No. 16 6 
