A reflection on evolution as myth. and particularly on Omah/Sasquatch/Bigfoot as our shadow in the natural world--occasioned by the author's trek through the Klamath Mountains in northwest California and southwest Oregon. Early on, the evidence of bears, ""black, shaggy beings emergent from millions of forested years,"" inspires the feeling that ""I had seen in four dimensions for a moment, as though some nascent or atrophied sense organ had given me a twinge."" Later, ""The biology lab associations of flat-worms made it seem strange to find them in the wilderness."" Wallace finds the mountain range ""vigilant,"" ""reticent,"" and ""venerable""; yet the rocks are also ""prankish,"" not neatly layered as in geology book diagrams but standing on their heads as a result of tectonic activity. In its turn, the plate tectonic theory is ""a current reminder of older myths in which a giant turtle supported the earth."" Sometimes Wallace's fancies are strained, or just not very productive: lampreys, he maintains, might be seen as an evolutionary counterpart of the vampire myth; and lakes and rivers remind him of human youth, whereas forests evoke maturity and grasslands old age. Finally, after passing the snow line to the land where the hairy, non-violent giants might abide, then entering a red-rock expanse that is ""close to our ideas of hell,"" and finally resting in an ethereal meadow, Wallace finds the ethical dimension of evolution as myth in its burden of new choices, its demonstration that ""humanity is not destined for anything."" A more modest endeavor than what Matthiessen or Schaller made of their quest for the snow leopard, akin to a meditative pastor's printed sermon.