I found this an eccentric, often lively, occasionally irritating account. It is part history, part chatty travelogue as Kim MacQuarrie leisurely makes his way down the Andes from Colombia, through Ecuador, Peru and Bolivia to Chile and Ushuaia on the island of Tierra del Fuego, the southernmost town in Argentina. He walks, hitches rides and takes trains and dusty, rusty buses as he marvels at the spectacular geography and strikes up conversations with locals along the way. "To travel down the Andes collecting stories the way others might fill a basket with ripe, exotic fruits."

In Colombia, the only story that engages him is the career of drug lord Pablo Escobar in the 1970s and '80s. He became a billionaire, owning 15 planes that each could carry 1,200 kilos of cocaine to the United States. MacQuarrie describes the hunt for him and his killing, in 1993, in novelistic style. It's a well-told tale, but isn't there more to say about an entire country?

Focusing on the Galápagos Islands of Ecuador, he changes his focus entirely, to Darwin's voyage there in 1837 and Darwin's puzzlement that there appeared to be different species of birds and turtles on different islands, and that some were species found nowhere else on Earth. Why would God play games like that? It began to dawn on him that species were not immutable, which lead him to the conclusions he arrived at in his transformative book of 1859, "On the Origins of Species."

In Peru, it's back to murder and mayhem. MacQuarrie visits Lima in 1986, during the height of the Shining Path's guerrilla war, begun in 1980 by Abimael Guzman. As a philosophy teacher in the poorest part of the country, he was galvanized into action by the poverty and illiteracy of most of the nation and was convinced that only a Marxist revolution could free the exploited masses, prime among them the Quechua-speaking Indians. The author closely follows the government's efforts to catch Guzman; it succeeded in 1992. (He has escaped at least twice since then.)

There's a quirky chapter on Hiram Bingham, who first found Machu Picchu in Peru but later lost his reputation after it was found that for years he had been stealing artifacts from the site.

Next, he examines Thor Heyerdahl's voyage in a balsa Inca-style raft across the Pacific from South America to Easter Island and disputes Heyerdahl's theories about where the island's settlers came from.

In Bolivia, we hear mostly about Che Guevara's failed guerrilla war and the last exploits there of Butch Cassidy and the Sundance Kid — the latter an odd and self-indulgent excursion, I find.

Finally, we arrive in Argentina and meet the last speaker of Yamana and learn the history and demise of the tribe.

MacQuarrie is an enthusiastic guide and is often amusing and occasionally enlightening. But the book is scattershot and, in its fondness for crooks and fighters, a decidedly odd exploration of South America.

Brigitte Frase is a book critic in Minneapolis.