It is hard to leave such camps and woods; nevertheless, to the large majority of travelers the middle region of the park is still more interesting, for it has the most striking features of all the Sierra scenery,—the deepest sections of the famous cañons, of which the Yosemite Valley, Hetch-Hetchy Valley, and many smaller ones are wider portions, with level parklike floors and walls of immense height and grandeur of sculpture. This middle region holds also the greater number of the beautiful glacier lakes and glacier meadows, the great granite domes, and the most brilliant and most extensive of the glacier pavements. And though in large part it is severely rocky and bare, it is still rich in trees. The magnificent silver fir (Abies magnifica), which ranks with the giants, forms a continuous belt across the park above the pines at an elevation of from seven to nine thousand feet, and north and south of the park boundaries to the extremities of the range, only slightly interrupted by the main cañons. The two-leaved or tamarack pine makes another less regular belt along the upper margin of the region, while between these two belts, and mingling with them, in groves or scattered, are the mountain hemlock, the most graceful of evergreens; the noble mountain pine; the Jeffrey form of the yellow pine, with big cones and long needles; and the brown, burly, sturdy Western juniper. All these, except the juniper, which grows on bald rocks, have plenty of flowery brush about them, and gardens in open spaces.
Here, too, lies the broad, shining heavily sculptured region of primeval granite, which best tells the story of the glacial period on the Pacific side of the continent. No other mountain chain on the globe, as far as I know, is so rich as the Sierra in bold, striking, well-preserved glacial monuments, easily understood by anybody capable of patient observation. Every feature is more or less glacial, and this park portion of the range is the brightest and clearest of all. Not a peak, ridge, dome, canon, lake basin, garden, forest, or stream but in some way explains the past existence and modes of action of flowing, grinding, sculpturing, soil-making, scenery-making ice. For, notwithstanding the post-glacial agents—air, rain, frost, rivers, earthquakes, avalanches—have been at work upon the greater part of the range for tens of thousands of stormy years, engraving their own characters over those of the ice, the latter are so heavily emphasized and enduring they still rise in sublime relief, clear and legible through every after inscription. The streams have traced only shallow wrinkles as yet, and avalanche, wind, rain, and melting snow have made blurs and scars, but the change effected on the face of the landscape is not greater than is made on the face of a mountaineer by a single year of weathering.
Of all the glacial phenomena presented here, the most striking and attractive to travelers are the polished pavements, because they are so beautiful, and their beauty is of so rare a kind,—unlike any part of the loose earthy lowlands where people dwell and earn their bread. They are simply flat or gently undulating areas of solid resisting granite, the unchanged surface over which the ancient glaciers flowed. They are found in the most perfect condition at an elevation of from eight to nine thousand feet above sea level. Some are miles in extent, only slightly blurred or scarred by spots that have at last yielded to the weather; while the best preserved portions are brilliantly polished, and reflect the sunbeams as calm water or glass, shining as if rubbed and burnished every day, notwithstanding they have been exposed to plashing, corroding rains, dew, frost, and melting sloppy snows for thousands of years.
The attention of hunters and prospectors, who see so much in their wild journeys, is seldom attracted by moraines, however regular and artificial-looking; or rocks, however boldly sculptured; or cañons, however deep and sheer-walled. But when they come to these pavements, they go down on their knees and rub their hands admiringly on the glistening surface, and try hard to account for its mysterious smoothness and brightness. They may have seen the winter avalanches come down the mountains, through the woods, sweeping away the trees and scouring the ground; but they conclude that this cannot be the work of avalanches, because the stri show that the agent, whatever it was, flowed along the around and over the top of high ridges and domes, and also filled the deep cañons. Neither can they see how water could be the agent, for the strange polish is found thousands of feet above the reach of any conceivable flood. Only the winds seem capable of moving over the face of the country in the directions indicated by the lines and grooves.
The pavements are particularly fine around Lake Tenaya, and have suggested the Indian name Py-we-ack, the Lake of the Shining Rocks. Indians seldom trouble themselves with geological questions, but a Mono Indian once came to me and asked if I could tell him what made the rocks so smooth at Tenaya. Even dogs and horses, on their first journeys into this region, study geology to the extent of gazing wonderingly at the strange brightness of the ground, and pawing it and smelling it, as if afraid of falling or sinking.
In the production of this admirable hard finish, the glaciers in many places exerted a pressure of more than a hundred tons to the square foot, planing down granite, slate, and quartz alike, showing their structure, and making beautiful mosaics where large feldspar crystals form the greater part of the rock. On such pavements the sunshine is at times dazzling, as if the surface were of burnished silver.
Here, also, are the brightest of the Sierra landscapes in general. The regions lying at the same elevation to the north and south were perhaps subjected to as long and intense a glaciation; but because the rocks are less resisting, their polished surfaces have mostly given way to the weather, leaving here and there only small imperfect patches on the most enduring portions of cañon walls protected from the action of rain and snow, and on hard bosses kept comparatively dry by boulders. The short, steeply inclined canons of the east flank of the range are in some places brightly polished, but they are far less magnificent than those of the broad west flank.