USING DIGITAL GIS GEOLOGIC MAPS TO HELP TELL THE STORY AND RECONSTRUCT THE RESOURCES OF DECOMMISSIONED FOSSIL CYCAD NATIONAL MONUMENT, BLACK HILLS OF SOUTH DAKOTA

The National Park Service Geologic Resources Division recently digitized a 1957 USGS Mineral Investigations Field Studies Map MF-70 entitled “Preliminary geologic map of the southwest part of the Minnekahta quadrangle, Fall River County, South Dakota” that shows the location of Fossil Cycad National Monument and the corresponding geology. Coincidentally this is the same year that the monument was deauthorized; it was proclaimed a monument in 1922. This map will be a useful tool in examining the former location of the deauthorized monument as well as for pinpointing the locations of the now lost paleontological resources. The map is now GIS based and can be used to overlay with Google Earth images of today’s landscape as well as other historical imagery to better understand the science of the extinct Fossil Cycad National Monument. The history of Fossil Cycad is an important lesson to be learned about our geologic heritage, both good and not so good. It is hoped that this story can serve as a model for other geologic heritage areas to be preserved to the best extent possible so as not to become extinct too like Fossil Cycad National Monument.