A travel book is a deceptively difficult thing to write. Glorious vistas and scenic overlooks just don't translate well into printed text. Honestly, how many different ways can the sentence, "That mountain sure is pretty!" be expressed? Before long, travel books begin to read like the sports page of a small college paper-the editorial staff is ever more pressed to find a synonym for stomped. That's why the appearance of Bill Bryson's A Walk in the Woods on the bestseller lists is a happy thing.The book is the tale of Mr. Bryson's Big Idea-to walk the Appalachian Trail (for WORLD publisher Joel Belz's Big Idea about that same subject, see the July 4 issue). His idea came about when he moved to a small town in New Hampshire and found that the footpath at the edge of town was, in fact, part of the Appalachian Trail, the more than 2,000-mile hiking path running from Georgia to Maine. "A little voice in my head said 'Sounds neat! Let's do it!'" Friends and neighbors were more than happy to interject a little realism into his plans: "Nearly everyone I talked to had some gruesome story involving a guileless acquaintance who had gone off hiking the trail with high hopes and new boots and come stumbling back two days later with a bobcat attached to his head or dripping blood from an armless sleeve and whispering in a hoarse voice, 'Bear!'" Those were not unnatural reactions, he realized. "The American woods have been unnerving people for 300 years," he explains. "The inestimably priggish and tiresome Henry David Thoreau thought nature was splendid, splendid indeed, so long as he could stroll to town for cakes and barley wine, but when he experienced real wilderness ... he was unnerved to the core." Mr. Bryson remained undaunted (at least until he saw the price tags on the camping equipment). At Christmas, he included notes in his Christmas cards inviting friends and relatives to do all or part of the walk with him. The only respondent was Katz, an old friend from college who was currently an overweight, out-of-work ex-alcoholic. And therein is why A Walk in the Woods succeeds where most travel books fail. Like Hilaire Belloc in his masterful The Path to Rome (about his pilgrimage from France to the Vatican), Mr. Bryson realizes that all stories, even travel stories, are about people. Katz rises from liability to heroic character-if only for tucking his chin, shouldering his 45-pound pack, and pressing on at each new imposing mountain. Mr. Bryson is a good writer; we feel the mountains, and-more importantly-we feel that we know Katz and the other characters. The book isn't flawless, mind you. Mr. Bryson has occasional outbursts of annoying liberalism. He peppers the narrative with propaganda on global warming and environmental disaster. To his credit, though, he realizes that government-at least not the Park Service-isn't the answer. The parts of the trail that are run by private groups and outdoors clubs are invariably better maintained, safer, and more pleasant than parts where the government's in control. And Mr. Bryson doesn't seem to be a Christian, so his responses to some of those glorious vistas fail to give glory to whom glory is due. Still, it's a good book about a grand walk.