This map folio set is a collaborative research project between the United States Geological Survey (USGS) and the Arkansas Geological Survey (AGS). The primary objective of the project is to conduct a geological assessment of the lignite resources in this region of Arkansas through subsurface modeling techniques. AGS publication FF-LIG-GCP-015 consists of one (1) drill hole index map and a series of six (6) interpretive digital maps depicting the location, depth, and thickness of lignite resources in Columbia County, Arkansas. The industry name "Emerson" was originally assigned to the project area during the 1970s and 1980s by Phillips Coal and these names are retained in the title of this map folio publication. The North American Coal Corporation (NAC) purchased the original drill hole information from Phillips Coal and provided technical oversight to AGS staff that constructed the subsurface models for the lignite resource. NAC also provided permission to the AGS to publish the map folio set.