"In this splendid book a gifted observer and a terrific idea have come together in a real love match. In 1990, a century after the census bureau's famous observation of the frontier's imminent end, Dayton Duncan set out in an aging GMC Suburban to visit a large sampling of counties outside Alaska that have fewer than two persons per square mile--the bureau's old standard for places still in a frontier condition. There are 132 such counties. All are...