West of Rawlins on Interstate 80, Love and I in the Bronco came into a region a good deal Ratter than most of Iowa, with so little relief that there were no roadcuts for more than fifty miles. Among dry lakebeds dimpling the Separation Flats, our altitude was seven thousand feet, yet the distant horizon was close to the curve of the earth. In this unroughened milieu, we passed a sign informing us zakelijke energie vergelijken that we were crossing the Continental Divide. So level is the land there that the divide is somewhat moot. Cartographers seem to have difficulty determining where it is. Its location will vary from map to map. Moreover, it frays, separates, and, like an eye in old rope, surrounds a couple of million acres that do not drain either to the Atlantic or the Pacific-adding ambiguity to the word “divide.” With respect to underlying strata, we were running along the crest of an arch between two sedimentary basins, although nothing on the surface suggested that this was so, for the basins were completely filled. The Rats to our left were the Washakie Basin, to our right the Great Divide Basin-each like a bowl brimming over with Eocene alluvial soup. Younger deposits-maybe a mile’s thickness -had long since been washed or blown away, leaving a fifty-millionyear-old surface on which anything modem might fall. A shepherd on horseback stood out against the sky, more so than his sheep. Even from a distance, he zakelijke energie looked cold and uncomfortable. On this robust May afternoon, gray clouds, moving fast, were beginning to throw down hail. Love turned off the interstate, and the vehicle bucked south for a couple of miles in drab brown ruts that suddenly turned bright, almost white, as the ground jumped forward in time roughly fifty million years. This patch of thirty or forty acres was all that remained locally of a volcanic-ash fall that had covered large parts of Wyoming, Colorado, Kansas, and Nebraska and had reached as far as Texas. Radiometric dating has established the event at six hundred thousand years before the present-far along in Pleistocene time, and an extremely recent date in the history of the world when you reflect that the age of the earth is more than seven thousand times the age of that ash fall, just as the United States of America is more than seven thousand times as old as something that happened in the middle of last week.