"Index and Guide to Topographic Maps and Geologic Folios by the U.S. Department of Interior: Geological Survey"1946-1975unknownhttp://rightsstatements.org/vocab/NKC/1.0/enghttp://congressarchives.org/record/CAC_CC_001_9_0000_4_90The United States Department of the Interior provides an index to topographic maps and geologic folios as part of their Geological Survey. Users can order maps by names printed in red, as these are the only ones published. The document includes a wide range of information, specifying different areas and coordinates in Oklahoma and other parts of the United States. It also offers details on topographic field work, published topographic maps, and geologic folios, along with their respective folio numbers. The map scale is approximately 1 inch to 40 miles.