ProPublica collected and analyzed records from 2003 to present from all 32 oil and gas producing states, focusing on the 22 states that supplied the most complete data. In some states, where much of the drilling is done on federal or Native American land, ProPublica also collected data from the Bureau of Land Management, which oversees drilling and enforces regulations on federal land. We'll update each chart as state and federal agencies continue to supply us with data.
See the complete regulator's database here. And read our related report "State Oil and Gas Regulators Are Spread Too Thin to Do Their Jobs".