On a Columbus Day, over the course of a discursive, 15-mile ramble to Thoreau's grave at Concord, Mass., Mitchell (Living at the End of Time, 1990, etc.) ponders the old roads of the Minutemen on their way to battle and laments the vacuity of the contemporary soul of America. More than the domain of the great naturalist philosopher, Concord, to Mitchell, is the American version of Mecca and Lourdes. Eschewing paved roads, Mitchell and two somewhat otherworldly companions trek along the all but vanished Revolutionary War trails used by the colonials to fight the battle of Concord, ``the point here being to get to Concord in a seventeenth-century landscape.'' As they perambulate through brambles, scout out stream crossings, and throw some of their lunch to growling dogs in a Cerberean encounter, Mitchell considers similar quests (including Ponce de Le¢n's search for the Fountain of Youth), the prevalence throughout history of special places, and pre-European legends of the Gay Head cliffs on Martha's Vineyard. Concord excluded, Mitchell contends that present-day America lacks meaningful pilgrimage sites: ``The white Anglo-Saxon Protestants who forged this country were not given to taking long, ecstatic journeys to spiritual centers'' and the English Puritans eliminated all vestiges of Native American holy places. As the trio nears Concord, most of the account is taken up with the chronology of the 1775 battle with the British, ironically juxtaposed with the story of a war 100 years earlier, for the same site, between the colonists and the Native Americans of the region: In the pantheon of holy places, Concord has long persisted. Like the path the travelers take, this odyssey is not particularly linear; but it is told with humor and a naturalist's eye for the region's flora and fauna (with illustrations by Robert Leverett). A book to be read leisurely and contemplatively.