Before Bigfoot became a supermarket celebrity, a TV star, a freak-show prisoner and an overall joke, it was a creature of traditional mythology. An endless mystery.Robert Michael Pyle once asked a tabloid editor why he traffics in Bigfoot trash — like “I Was Bigfoot’s Love Slave!” and “Hillary Names Bigfoot as Running Mate!” — and the frank reply was, the real world is boring. People wouldn’t buy that stuff otherwise.“That was the saddest thing of all, to me,” Pyle said. “To one whose eyes are open, the world is never boring.”Pyle, an author and ecologist based in Gray’s River, will visit Vintage Books in Vancouver on Sunday afternoon to speak and sign copies of a new edition of his classic exploration of the facts, myths and cultural meaning of Southwest Washington’s resident legend.“Where Bigfoot Walks,” first published in 1995, has a new afterword in which Pyle considers the latest clues, discoveries and hints that keep pointing toward the genuine presence of a species of extremely shy humanoid giants — perhaps an evolutionary dead-end — in and around the Dark Divide, a triangle of remote, roadless land east of Mount St. Helens.Pyle, a Yale-trained ecologist and the author of 20 books, is plenty wary of fraud and skeptical of ignorance, flimsy claims, fanciful theories. He prefers what’s simple, logical, provable.