Wyoming, at first glance, would appear to be an arbitrary segment of the country. Wyoming and Colorado are the only states whose borders consist of four straight lines. That could be looked upon as an affront to nature, an utterly political conception, an ignoring of the outlines of physiographic worlds, in disregard of rivers and divides. Rivers and divides, however, are in some ways unworthy as boundaries, which are meant to imply a durability that is belied by the function of rivers and divides. They move, they change, and they go away. Rivers, almost by definition, are young. The oldest river in the United States is called the New River. It has existed (in North Carolina, Virginia, and West Virginia) for a little more than one and a half per cent of the history of the world. In epochs and eras before there ever was a Colorado River, the zakelijke energie vergelijken formations of the Grand Canyon were crossed and crisscrossed, scoured and dissolved, deposited and moved by innumerable rivers. The Colorado River, which has only recently appeared on eaith, has excavated the Grand Canyon in very little time. From its beginning, human beings could have watched the Grand Canyon being made. The Green River has cut down through the Uinta Mountains in the last few million years, the Wind River through the Owl Creek Mountains, the Laramie River through the Laramie Range. The mountains themselves came up and moved. Several thousand feet of basin fill has recently disappeared. As the rock around Rawlins amply shows, the face of the country has frequently changed. Wyoming suggests with emphasis the page-one principle of reading in rock the record of the earth: Surface appearances are only that; topography grows, shrinks, compresses, spreads, disintegrates, and zakelijke energie disappears; every scene is temporary, and is composed of fragments from other scenes. Four straight lines-like a plug cut in the side of a watermelon-should do as well as any to frame Wyoming and its former worlds. A geologist who grew up in Wyoming has grown up among
mountains that in terms of plate-tectonic theory are the least explainable in the world.