Map showing spatial and temporal relations of mountain and continental glaciations on the Northern Plains, primarily in northern Montana and northwestern North Dakota [unknown]

David S. Fullerton, Roger B. Colton, Charles A. Bush, Arthur W. Straub
2004 Scientific Investigations Map   unpublished
doi:10.3133/sim2843 fatcat:klpha6mkgbduhd6jdkcyx3tlu4