The scene is western Montana, and Philip Caputo has come upon Don Kray, a 75-year-old cowpoke who laments that cowboys have been displaced by fly fishermen as folk heroes out there.

Kray tells Caputo about the wife who left him, came back after his second wife died, then left again because her potbellied pig had taken a dislike to him. Later, he shows a picture of a mare that had thrown him 10 years earlier. "Bucked me right off, ironed me out good, goddamned right she did, and it feels different at 65 than it does at 16."

Caputo's 1977 memoir of his Marine service in the early years of the Vietnam War ("Rumor of War") is widely considered one of the best books to come out of that chapter in U.S. history. Now the Pulitzer Prize-winning journalist has brought his keen reporter senses, including the ability to find and give voice to interesting characters, to another genre: the experiential "on-the-road" story.

In "The Longest Road," Caputo follows (and occasionally cites) the accounts of earlier travelers, from the 19th century's Francis Parkman ("The Oregon Trail") through Jack Kerouac ("On the Road"), John Steinbeck ("Travels With Charley") and William Least Heat Moon ("Blue Highways"). Throw in, too, the journals of Lewis and Clark, whose path through the Northwest Caputo followed and whose wonderment at the beauty of the land and all that was on it he shared.

His route took him, his wife and two Irish setters from the southernmost drivable point in the United States, at Key West, Fla., diagonally across the country and through western Canada to the northernmost, at Deadhorse, Alaska. His objective: to learn what holds this sprawling country and its people, its peoples, together.

The idea for such a rambling quest had come to him years ago when he stood on Barter Island in the Beaufort Sea and thought about Key West, where he had lived in the 1970s and '80s.

"The Inupiat schoolkids here pledge allegiance to the same flag as the children and grandchildren of Cuban immigrants on Key West, six thousand miles away," he writes. "Native Americans and Cuban Americans on two islands as far apart as New York is from Moscow, yet in the same country. How remarkable."

He found people who represented "the America I didn't recognize — spiteful and cruel," but he also found a West Virginia couple working with homeless people in Florida, volunteers aiding in post-tornado cleanup in Alabama, young protesters with "a Jeffersonian vision" resisting big energy development in Montana and Indians in the Pacific Northwest working to preserve their culture and language.

What did he learn about his country, about what holds it together? Take the journey with him. It's a good ride, and a good read.

In 1988, Chuck Haga followed John Steinbeck's route in "Travels With Charley" and sent weekly reports back to the Star Tribune, where he was then a reporter.