At the outset this traces the course of exploration and settlement in colonial New York (since both centered on the mouth and valley of the Hudson) and thus duplicates much that is found elsewhere; some of the later history--especially the skim of the 19th century--is similarly commonplace. Neither are all the appropriate topics covered--there is only incidental mention, for instance, of the valley's leading agricultural pursuits, dairying and fruit growing. And the book is insufficiently illustrated, lacking photos of the breadth and banks of the Hudson, its old buildings, its famous bridges, all touted in the text (most of the illustrations are historic in nature). Which may be less of a handicap than it appears, however, since the likely readers are youngsters who live in the area--this because the book features such localized particulars as the chain that was twice stretched across the river during the Revolution (to block British ships); the heyday of whaling (when Hudson, N.Y., rivaled Nantucket); early riverside industries; steamboat racing; the Hudson River school of painting (less literal than suggested here, however, and not ""the only school of painting ever developed in America""). Also treated (i.e. drubbed) is the feudal land system that was not abolished until 1846. An informal profile of some interest, then, if not as steeped in local lore as Carl Carmer's volume in the Holt series.