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Mountains that were completely covered -lost to view somewhere below the water-laid sediments and deep volcanic sand-outnumbered the mountains that barely showed through. At its maximum, the broad planar surface occupied nearly all of Wyoming-upward of ninety per cent-and on it meandered slow streams, making huge bends and oxbows. As events were about to prove, the deposition would rise no higher. This-in the late Miocene-was the level of maximum fill. For something began to elevate the region-the whole terrane, the complete interred family of underthrust, upthrust, overthrust mountains-to lift them swiftly about a mile. “The uplift was: not absolutely zakelijke energie vergelijken uniform everywhere,” Love said. “But nothing evefi is.” What produced this so-called epeirogeny is a subject of vigorous and sometimes virulent argument, but the result, continuing to this day, is as indisputable as it has been dramatic. It is known in geology as the Exhumation of the Rockies. From around and over the Wyoming ranges alone, about fifty thousand cubic miles have been dug out and taken away, not to mention comparable excavations in the neighboring cordillera. Though the process has been going on for ten million years, it is believed to have been particularly energetic in the past million and a half, in part because of the amount of rain that fell on the peripheries of continental ice. In response to the uplift, the easygoing streams that had aimlessly wandered the Miocene plain began to straighten, rush, and cut, moving their boulders and gravels in the way that chain saws move their teeth. The zakelijke energie streams lay in patterns that had no relationship to the Eocene topography buried far below. Some of them, rushing along through what is now the Wyoming sky, happened to cross the crests of buried ranges. After they worked their way down to the ranges, they sawed through them. Some effects were even odder than that.

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