Coal Exploration Drill-Hole Data for Alaska, Colorado, Illinois, Iowa, Kansas, Missouri, Montana, North Dakota, Virginia, and Wyoming

Coal exploration drill-hole data from 5,037 wells located in Alaska, Colorado, Illinois, Iowa, Kansas, Missouri, Montana, North Dakota, Virginia, and Wyoming are provided in this data release. The wells are located in sixty-eight counties and were drilled between 1971 and 1981, primarily by Phillips Petroleum Company (Phillips). The hard-copy paper data were donated to the U.S. Geological Survey (USGS) in 2001 by the North American Coal Corporation, which purchased the Phillips assets as part of a larger dataset. Under the terms of the agreement with North American Coal Corporation, the data were deemed proprietary until February 2011, a period of 10 years after the donation. The drill-hole data contained in this release were not previously included in USGS Open-File Report Series 2011-1261: Shallow Coal Exploration Drill-Hole Data -- Alabama, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, South Carolina, Tennessee, and Texas. The Alaska, Colorado, Illinois, Iowa, Kansas, Missouri, Montana, North Dakota, Virginia, and Wyoming data are made publicly available by this report.