The Marcellus well and production data included in this data set were obtained from the geological survey offices of Ohio, Pennsylvania and West Virginia. Both surface and bottom location points are depicted wherever separate coordinates are available. U.S. Department of Energy research wells are also included. Production data are available by, in some cases, individual well. In other instances summary production data are used. The points in this data set indicate the geographic locations of Marcellus unconventional wells. These data were compiled for use in the Atlas of Unconventional Hydrocarbon Resources web viewer.