Elk, grouse, blacktail deer, antelope, rattlesnakes, prairie dogs, skunks, badgers, owls, whistling martens, wild sheep, and the grizzlies we never saw alive were all part of the great West. So were the bucking cayuses and kicking mules with which we lived, numerous ranchers, prospectors, soldiers, sportsmen, and guides. Once we were joined by a sheriff looking for an escaped desperado from Red Lodge Prison. Just before I left the Yellowstone, I visited the hot springs and geysers. With more than 4,000 vents, the geyser basins are steaming areas in the forest. At Mammoth, the carbonate terraces show exquisite ripples and sculptured cups in steps. One hotter group of waters, through the igneous lavas and granites, becomes full of silica and deposits sinter. The other, through limestones, deposits travertine. The alkaline siliceous waters deposit such strong silica edifices as to hold the explosive steam boilers of the geysers. Both silica and lime deposits are led to gorgeous sculpturing and to brilliant colors at their borders caused by the blue-green algae, which live at temperatures up to 150° Fahrenheit. The boiling waters have been superheated volcanically since Tertiary volcano times, when first dark magnesian, and afterwards siliceous, lavas were ejected. Here is the same order Daly and I found in Vermont; the dark rocks first, rifting through slate, the granites last, with quartz cutting the dark rocks. The cavities among the Yellowstone geysers show quartz. The surprise to me was that the geyser basins were eternally breaking down, cracking, dissolving, making new geysers in the forest. Instead of being chiefly deposition, the hot spring action is chiefly erosion. It is a vast cycle of hot magma gases and rainwaters from Tertiary times to now; from 20 million years ago to now. A long time. Remember that the last retreat of the glacier-period ice was only 20,000 years ago. That ice found the geyser basins in full swing. A thousand times farther back were the Yellowstone volcanoes in full activity, and they kept going while the continent lifted and pushed the Gulf of Mexico from the Great Plains to where it is now. And yet that 20 million years was only a twenty-fifth of the time back to the trilobites, and a Yellowstone seabottom bed of that age is under all the lavas. Our schoolbook history is pretty small.