Newberry, J.S., 1858, Geologic maps no. 1 and no. 2, Rio Colorado of the West: 2 sheets, scale 1:760,320, accompanying Newberry (1861). Authors Newberry, J.S. Publication Date 1858 Citation 2 sheets, scale 1:760,320, accompanying Newberry (1861). AzGeoBib RefNum 7421