Early next morning Clark and I made up a bag of lunch, shouldered our instruments, and set out for a day on the glacier. Our slow, laborious ascent of the valley was not altogether uninteresting. Constant views obtained of moraines on either side gave us much pleasure and study. It was instructive to observe that the bases of their structure were solid floors of lava, upon which, in rude though secure masonry, were piled embankments not less than half a mile wide and four hundred feet high. Among the huge rocks which formed the upper structure the tree-forms were peculiar. Apparently every tree had made an effort to fill some gap and round out the smooth general surface. No matter how deeply twisted between high bowlders, the branches spread themselves out in a continuous, dense mat, stretching from stone to stone. It was only rarely, and in the less elevated parts of the moraine, that we could see a trunk. The whole effect was of a causeway of rock overgrown by some dense, green vine.
Similar patches of stunted trees grew here and there over the bottom of our broad amphitheatre. Oftentimes we threaded our way among dense thickets of pines, never over six or eight feet in height, having trunks often two and three feet in diameter, and more than once we walked over their tops, our feet sinking but two or three inches into the dense mat of foliage. Here and there, half buried in the drift, we came across the tall, noble trunks of avalanche-killed trees. In comparing their straight, symmetrical growth with the singularly matted condition of the living-dwarfed trees, I find the indication of a great climatic change. Not only are the present avalanches too great to permit their growth, but the violent cold winds which drift over this region bend down the young trees to such an extent that there are no longer tall, normal specimens. Around the upper limits of aborescent vegetation we passed some most enchanting spots; groves, not over eight feet in height, of large trees whose white trunks and interwoven boughs formed a colonnade, over which stretched thick, living thatch. Under these strange galleries we walked upon soft, velvety turf and an elastic cushion of pine-needles; nor could we resist the temptation of lying down here to rest beneath the dense roof. As we looked back, charming little vistas opened between the old and dwarfed stems. In one direction we could see the moraine with its long, graded slope and variegated green and brown surface; in another, the open pathway of the old glacier worn deeper and deeper between lofty, forest-clad spurs; and up to the great snow mass above us, with its slender peak in the heavens looking down upon magnificent sweep of névé.
Only the strong desire for glaciers led us away from these delightful groves. A short tramp over sand and bowlders brought us to the foot of a broad, irregular, terminal moraine. Two or three milky cascades poured out from under the great bowlder region and united to form two important streams. We followed one of these in our climb up the moraine, and after an hour’s hard work found ourselves upon an immense pile of lava blocks, from which we could overlook the whole.
In irregular curve it continues not less than three miles around the end of the glacier, and in no place that I saw was less than a half mile in width. Where we had attacked it the width cannot be less than a mile, and the portion over which we had climbed must reach a thickness of five or six hundred feet.
About a half mile above us, though but little lifted from our level, undulating hillocks of ice marked the division between glacier and moraine; above that, it stretched in uninterrupted white fields. The moraine in every direction extended in singularly abrupt hills, separated by deep, irregular pits and basins of a hundred and more feet deep.
As we climbed on, the footing became more and more insecure, piles of rock giving way under our weight. Before long we came to a region of circular, funnel-shaped craters, where evidently the underlying glacier had melted out and a whole freight of bowlders fallen in with a rush. Around the edges of these horrible traps we threaded our way with extreme caution; now and then a bowlder, dislodging under our feet, rolled down into these pits, and many tons would settle out of sight. Altogether it was the most dangerous kind of climbing I have ever seen. You were never sure of your foothold. More than once, when crossing a comparatively smooth, level bowlder-field, the rocks began to sink under us, and we sprang on from stone to stone while the great mass caved and sank slowly behind us. At times, while making our way over solid-seeming stretches, the sound of a deep, sub-glacial stream flowing far beneath us came up faint and muffled through the chinks of the rock. This sort of music is not encouraging to the nerves. To the siren babble of mountain brook is added all the tragic nearness of death.
We looked far and wide in hope of some solid region which should lead us up to the ice, but it was all alike, and we hurried on, the rocks settling and sinking beneath our tread, until we made our way to the edge, and climbed with relief upon the hard, white surface. After we had gained the height of a hundred feet, climbing up a comparatively smooth slope between brooks which flowed over it, a look back gave a more correct idea of the general billowy character of our moraine; and here and there in its deeper indentations we could detect the underlying ice.
It is, then, here as upon the McCloud Glacier. For at least a mile’s width the whole lower zone is buried under accumulation of morainal matter. Instead of ending like most Swiss glaciers, this ice wastes chiefly in contact with the ground, and when considerable caverns are formed the overlying moraine crushes its way through the rotten roof, making the funnels we had seen.
Thankful that we had not assisted at one of these engulfments, we scrambled on up the smooth, roof-like slope, steadying our ascent by the tripod legs used as alpine stock. When we had climbed perhaps a thousand feet the surface angle became somewhat gentler, and we were able to overlook before us the whole broad incline up to the very peak. For a mile or a mile and a half the sharp, blue edges of crevasses were apparent here and there, yawning widely for the length of a thousand feet, and at other places intersecting each other confusedly, resulting in piled-up masses of shattered ice.
We were charmed to enter this wild region, and hurried to the edge of an immense chasm. It could hardly have been less than a thousand or twelve hundred feet in length. The solid, white wall of the opposite side—sixty feet over—fell smooth and vertical for a hundred feet or more, where rough wedged blocks and bridges of clear blue ice stretched from wall to wall. From these and from numerous overhanging shelves hung the long, crystal threads of icicles, and beyond, dark and impenetrable, opened ice-caverns of unknown limit. We cautiously walked along this brink, examining with deep interest all the lines of stratification and veining, and the strange succession of views down into the fractured regions below.