Mr. Pyle says he is not interested in whether Sasquatch is or is not real. Rather, he aims to examine the myth surrounding the controversial creature and the human characters who have concerned themselves with its fate. He describes his pursuit as "a chance to immerse myself in the putative habitat of Bigfoot. And perhaps a way into its mind, or at least into the part of my own mind where Bigfoot dwells." He recounts a year of studies in flashbacks woven into a narrative of a month long hike through territory in southwestern Washington, known as the Dark Divide, that is rich in Sasquatch sightings.

He also talks a lot about butterflies Bigfoot may or may not be familiar with. His Wintergreen won the John Burroughs Medal for the best natural history book in 1987, establishing his credentials as an ecology writer, but he seems to be a lepidopterist at heart. In addition to having written The Audubon Society Field Guide to North American Butterflies, he is now editing a collection of butterfly writing by Vladimir Nabokov. The idea of a lepidopterist on the trail of a 1,000-pound giant hairy thing that is sometimes said to lift cows into trees contributes, for me, to an accidental comic effect.

Mr. Pyle is not a slight lepidopterist¹, however: he describes his long-bearded self in full pack and custom-made hiking boots (he has a foot problem) as weighing 330 pounds. In fact, for the first few pages into the hike I thought I was going to have to call for help as he heaved and dehydrated his way up and down hills, once nearly falling to his death. Fortunately, he survives long enough to recall a few of the Northwest Indian tales of hairy creatures such as Dzonoqua, Bukwus, Bokbokwolli nooksiway, Stick Man and Se-at-tlh (Mr. Pyle suggests that the name of the capital of grunge might be an etymological relative of Sasquatch). Next, he lays out some of the key issues of Sasquatchology: Has Sasquatch embraced second-growth forest as a living area? Does it travel in tribes or alone? If found, should it be killed? The rest of the time he details the habitat. He over details it; this guy knows the name of absolutely everything that grows in the woods. Which turns out to be the problem with sending a lepidopterist out after Sasquatch: he might not be able to see Bigfoot's forest through the pipsissewa², a batch of which he duly notes.

Not very far into the trip, Mr. Pyle begins to sound more like a believer than he cares to admit. "If a lagomorph³ most often identified with alpine granite can thrive in sea-level basalt and mid-elevation woodpiles, what does that say for a primate's chances of switching from forest to scrub?" he asks; I get the distinct feeling he thinks it says the primate's chances are very good. He also says, "In the absence of specimens, no one can prove that Bigfoot is not out there." And sure enough, more than once he has what might be called a limited encounter. He remains skeptical of even his own possible brushes with Sasquatch, but by the time you get to the appendix, entitled "A Protocol for Encounter," you're not surprised that he thinks Sasquatch killers, scientists or others, ought to be hit with the book: "If not manslaughter, the crime should at least be an imprisonable felony."

The school of Bigfoot thought that Mr. Pyle's book most neatly sides with is that usually associated with Peter Byrne, whom Mr. Pyle describes as "suave and handsome" in appearance, "enhanced by his Oxbridge accent, pressed khakis, sweat-stained safari hat and silk cravat." "I have yet to share a campfire" with Mr. Byrne, Mr. Pyle writes, "but we have sat around fireplaces in both our homes, sharing good ale, chenin blanc or single-malt whisky, trading tales from Nepal or New Guinea, comparing signatures of Tenzing Norgay." Mr. Byrne is a staunch advocate of the no-kill policy, and he often suggests that Bigfoot hunters cooperate in the search — something as unlikely as an imminent Sasquatch find. But what will Mr. Byrne make of the chapter in which Mr. Pyle runs around naked in the woods? ("I was Bigfoot," he claims.) I can't say.

For those unfamiliar with the Bigfoot legend, Where Bigfoot Walks is a good primer. For those up to speed, the story Mr. Pyle has recorded of a Sasquatch-like encounter as told around the campfire by a former Haisla Nation chief from coastal British Columbia may be worth all the rehashing; it is one of the best I've ever read. I found a lot of Where Bigfoot Walks to be a little annoying, mostly because Mr. Pyle does what he accuses various Bigfoot hunters of doing — using the creature for his own cause, in this case as a paean to the Northwest's evaporating nature. As a paean, it is O.K., but its point — that if Sasquatch is in jeopardy, then so are both the mythic and the no mythic qualities of the woods — seems obvious. In the end, I mostly savored the Bigfoot encounters and the crisp writing about butterflies. There is a description of ghost moths mating fluorescently in the moonlit sky that makes them seem fairylike, even haunting. After reading that, I hope to be out in the woods camping sometime and see a ghost moth light up the night.

1. lep·i·dop·ter·ist: n. An entomologist specializing in the study of butterflies and moths.
2. pip·sis·se·wa: n. Any of several evergreen plants of the genus Chimaphila, especially the Eurasian species C. umbellata, having white or pinkish flowers grouped in a terminal corymb. Also called prince's pine.
3.lag·o·morph: n. Any of various plant-eating mammals having fully furred feet and two pairs of upper incisors and belonging to the order Lagomorpha, which includes the rabbits, hares, and pikas. –lago·morphic, lago·morphous adj.