Two new U.S. Geological Survey publications that highlight historical hydraulic fracturing trends and data from 1947 to 2010 are now available.Hydraulic fracturing is presently the primary stimulation technique for oil and gas production in unconventional resource reservoirs. Comprehensive, published, and publicly available information regarding the extent, location, and character of hydraulic fracturing in the United States is scarce. “These national-scale data and analyses will provide a basis for making comparisons of current-day hydraulic fracturing to historical applications,” said USGS scientist and lead author Tanya Gallegos.