Diffendal, Jr., RobertMichael R. VoorhiesE. Jane VoorhiesH. E. LaGarryC. L. TimperleyM. E. PerkinsGeology mapped principally from 1991-2000 by RFD, M.RV, E.JV, H. LG , and C.LT Editing and layout by R.F. Diffendal, Jr. and D. Ebbeka Map production by J. Nothwehr and L. Howard.Revised slightly 6 January 2009, 20 July 2010, 5 October 2010, 10 September 2012.PDFhttps://digitalcommons.unl.edu/natrespapers/304engUniversity of Nebraska, Conservation and Survey DivisionPublicGeologic Map of the O'Neill 1º X 2º Quaudrangle, Nebraska with configuration maps of surfaces of formationsMapsNebraska1991-2000 University of Nebraska-Lincoln