Around the dome and well up toward the summit of the main peak, the snow-shed was well marked with tracks of the mule deer and the pretty stitching and embroidery of field mice, squirrels, and grouse; and on the way back to camp I came across a strange track, somewhat like that of a small bear, but more spreading at the toes. It proved to be that of a wolverine. In my conversations with hunters, both Indians and white men assure me that there are no bears in Nevada, notwithstanding the abundance of pine-nuts, of which they are so fond, and the accessibility of these basin ranges from their favorite haunts in the Sierra Nevada and Wahsatch Mountains. The mule deer, antelope, wild sheep, wolverine, and two species of wolves are all of the larger animals that I have seen or heard of in the State.
XV. Glacial Phenomena in Nevada[[20]]
The monuments of the Ice Age in the Great Basin have been greatly obscured and broken, many of the more ancient of them having perished altogether, leaving scarce a mark, however faint, of their existence—a condition of things due not alone to the long-continued action of post-glacial agents, but also in great part to the perishable character of the rocks of which they were made. The bottoms of the main valleys, once grooved and planished like the glacier pavements of the Sierra, lie buried beneath sediments and detritus derived from the adjacent mountains, and now form the arid sage plains; characteristic U-shaped cañons have become V-shaped by the deepening of their bottoms and straightening of their sides, and decaying glacier headlands have been undermined and thrown down in loose taluses, while most of the moraines and striae and scratches have been blurred or weathered away. Nevertheless, enough remains of the more recent and the more enduring phenomena to cast a good light well back upon the conditions of the ancient ice sheet that covered this interesting region, and upon the system of distinct glaciers that loaded the tops of the mountains and filled the cañons long after the ice sheet had been broken up.
The first glacial traces that I noticed in the basin are on the Wassuck, Augusta, and Toyabe ranges, consisting of ridges and cañons, whose trends, contours, and general sculpture are in great part specifically glacial, though deeply blurred by subsequent denudation. These discoveries were made during the summer of 1876-77. And again, on the 17th of last August, while making the ascent of Mount Jefferson, the dominating mountain of the Toquima range, I discovered an exceedingly interesting group of moraines, cañons with V-shaped cross sections, wide neve amphitheatres, moutoneed rocks, glacier meadows, and one glacier lake, all as fresh and telling as if the glaciers to which they belonged had scarcely vanished.
The best preserved and most regular of the moraines are two laterals about two hundred feet in height and two miles long, extending from the foot of a magnificent cañon valley on the north side of the mountain and trending first in a northerly direction, then curving around to the west, while a well-characterized terminal moraine, formed by the glacier towards the close of its existence, unites them near their lower extremities at a height of eighty-five hundred feet. Another pair of older lateral moraines, belonging to a glacier of which the one just mentioned was a tributary, extend in a general northwesterly direction nearly to the level of Big Smoky Valley, about fifty-five hundred feet above sea level.
Four other cañons, extending down the eastern slopes of this grand old mountain into Monito Valley, are hardly less rich in glacial records, while the effects of the mountain shadows in controlling and directing the movements of the residual glaciers to which all these phenomena belonged are everywhere delightfully apparent in the trends of the cañons and ridges, and in the massive sculpture of the neve wombs at their heads. This is a very marked and imposing mountain, attracting the eye from a great distance. It presents a smooth and gently curved outline against the sky, as observed from the plains, and is whitened with patches of enduring snow. The summit is made up of irregular volcanic tables, the most extensive of which is about two and a half miles long, and like the smaller ones is broken abruptly down on the edges by the action of the ice. Its height is approximately eleven thousand three hundred feet above the sea.
A few days after making these interesting discoveries, I found other well-preserved glacial traces on Arc Dome, the culminating summit of the Toyabe Range. On its northeastern slopes there are two small glacier lakes, and the basins of two others which have recently been filled with down-washed detritus. One small residual glacier lingered until quite recently beneath the coolest shadows of the dome, the moraines and névé-fountains of which are still as fresh and unwasted as many of those lying at the same elevation on the Sierra—ten thousand feet—while older and more wasted specimens may be traced on all the adjacent mountains. The sculpture, too, of all the ridges and summits of this section of the range is recognized at once as glacial, some of the larger characters being still easily readable from the plains at a distance of fifteen or twenty miles.
The Hot Creek Mountains, lying to the east of the Toquima and Monito ranges, reach the culminating point on a deeply serrate ridge at a height of ten thousand feet above the sea. This ridge is found to be made up of a series of imposing towers and pinnacles which have been eroded from the solid mass of the mountain by a group of small residual glaciers that lingered in their shadows long after the larger ice rivers had vanished. On its western declivities are found a group of well-characterized moraines, cañons, and roches moutonnées, all of which are unmistakably fresh and telling. The moraines in particular could hardly fail to attract the eye of any observer. Some of the short laterals of the glaciers that drew their fountain snows from the jagged recesses of the summit are from one to two hundred feet in height, and scarce at all wasted as yet, notwithstanding the countless storms that have fallen upon them, while cool rills flow between them, watering charming gardens of arctic plants—saxifrages, larkspurs, dwarf birch, ribes, and parnassia, etc.—beautiful memories of the Ice Age, representing a once greatly extended flora.
In the course of explorations made to the eastward of here, between the 38th and 40th parallels, I observed glacial phenomena equally fresh and demonstrative on all the higher mountains of the White Pine, Golden Gate, and Snake ranges, varying from those already described only as determined by differences of elevation, relations to the snow-bearing winds, and the physical characteristics of the rock formations.
On the Jeff Davis group of the Snake Range, the dominating summit of which is nearly thirteen thousand feet in elevation, and the highest ground in the basin, every marked feature is a glacier monument—peaks, valleys, ridges, meadows, and lakes. And because here the snow-fountains lay at a greater height, while the rock, an exceedingly hard quartzite, offered superior resistance to post-glacial agents, the ice-characters are on a larger scale, and are more sharply defined than any we have noticed elsewhere, and it is probably here that the last lingering glacier of the basin was located. The summits and connecting ridges are mere blades and points, ground sharp by the glaciers that descended on both sides to the main valleys. From one standpoint I counted nine of these glacial channels with their moraines sweeping grandly out to the plains to deep sheer-walled névé-fountains at their heads, making a most vivid picture of the last days of the Ice Period.