OK 30min USGS Quadrangles GEOREF

This zip file includes a georeferenced (Projected > UTM > NAD 1927 > Zone 14 North) set of turn of the century 30' USGS Quadrangle maps in Oklahoma. The maps range in date from 1890 to 1916. I have also georeferenced the index map, but please note that the dates for individual maps shown on the index are not all correct. Each map file name includes the map name and the correct date. Pdf files are 30' USGS Quadrangles for adjoining states (Kansas and Arkansas).