Free Centennial by James A. Michener Page B

eight million years ago, it once more began to tumble out of the mountains with greatly increased velocity, cutting and swirling and spreading far across the plains. It was engaged upon a gargantuan task, to scour away every vestige of the enormous quantity of land that had been contributed by the New Rockies. In some places it had to remove up to a thousand feet of burden; from extensive areas it had to cut away at least three hundred feet. But it succeeded ... except where that extra-hard caprock protected its monolith.
    No matter how wild the torrents that raged down from the mountains, nor how compulsive the flash floods that cascaded across the plain after some torrential downpour, the monolith persisted. It covered an area no more than a quarter of a mile long, two hundred yards wide, but it resisted all assaults of the river. For millions of years this strange and solitary monolith maintained its integrity.
    Neighboring sandstone covers were breached, and when they were gone, the softer areas they had protected were easily cut down by the river. Winds helped; meltwater from ice did its damage; and as the eons passed, the river completed its task: all remnants of land deposited by the New Rockies were swept away, except the solitary monolith.
    And then, about two million years ago, the central portion of the caprock weakened, cracked during a heavy winter, and broke away. The softer rock which it had been protecting quickly deteriorated—say, over a period of two hundred thousand years—until it was gone.
    Two pillars remained, about a quarter of a mile apart, each somewhat elongated in shape; the western was over five hundred feet long and two hundred feet wide, the eastern only three hundred and eighty feet long and a hundred and ninety wide. The western pillar was taller, too, standing three hundred and twenty feet above its pediment; the eastern, only two hundred and eighty.
    They were extraordinary, these two sentinels of the plains. Visible for miles in each direction, they guarded a bleak and silent empire. They were the only remaining relics of that vast plain which the New Rockies had deposited; each bit of land the sentinels surveyed dated back to ancient times before the mountains were born.
    The fourth special place is rather embarrassing to mention, after this parade of fractured cliffs, valleys packed with gold and high monuments of integrity; but eleven thousand years ago, when the main features of the New Rocky Mountain area had long been determined and the land looked pretty much as it looks today, a small, wandering muddy stream joined the river at the spot where Centennial was to be. It came in from the north and in its day must have been a helpful agent to the parent river in scouring off the debris sent down by the mountains. Now it was a miserable thing, carrying little water and serving more as a drainage ditch than a rivulet.
    But along its western bank, not far from where it joined the river, its probing fingers had recently penetrated into a pocket of soluble stone lying some seven feet below the surface of the land. It formed a secret cave less than six feet long and only four feet wide. It would scarcely have been noticed except for a dramatic event which would occur in relation to it eleven thousand years after its creation by the meandering stream.
    And so the stage is set. One billion, seven hundred million years of activity, including the building of at least two high mountain ranges and the calling into being of vast seas, have produced a land which is ready to receive living things.
    It is not a hospitable land, like that farther east in Kansas or back near the Appalachians. It is mean and gravelly and hard to work. It lacks an adequate topsoil for plowing. It is devoid of trees or easy shelter. A family could wander this land for weeks and never find enough wood to build a house.
    It lacks water—my God, how it lacks water. Rainfall at Centennial is only thirteen inches a year, when