Media type: Book Title: Conservation and the gospel of efficiency : the progressive conservation movement, 1890 - 1920 Contributor: Hays, Samuel P. [Author] imprint: Pittsburgh, Pa.: University of Pittsburgh Press, 1999 Issue: [Nachdr.] Extent: XVI, 297 S. Language: English ISBN: 0822957027 RVK notation: MC 6200 : Konservatismus Keywords: Conservation of natural resources United States History ; Environmental policy United States History Origination: Footnote: Originally published: Cambridge : Harvard University Press, 1959, in series: Harvard historical monographs, 40 - Includes bibliographical references and index