Geological and Natural History Survey of MinnesotaWinchell, Alexander, 1824-1891Winchell, N. H. (Newton Horace), 1839-1914Cartographic Details: Scale approximately 1:330,000 (W 92°1'--W 89°30'/N 48°14'--N 47°3'). Relief shown by hachures. Cover title: Winchell's Geological map of the iron-bearing rocks of northeastern Minnesota. -- Advance copy. Includes descriptive text inside cover.18 x 76 centimeters on sheet 20 x 74 centimetersJPEGUMN_ALMA:9957656730001701engGeological and Natural History Survey of Minnesota ; St. Paul, MinnesotaPublicPreliminary geological map of the iron bearing rocks of the northeastern part of MinnesotaMapsMinnesota1887University of Minnesota