Concerns about hydraulic fracturing are behind many states’ reluctance to tap the economic benefits created by natural gas development. Hydraulic fracturing—“fracking”—is an oil and gas extraction method that uses hydraulic pressure to break up rock. Millions of gallons of pressurized liquids, usually a water-based mixture of sand and chemical additives, are pumped deep underground to help release trapped gas. This report provides an introduction to the domestic natural gas picture, explores the motivation behind state legislative involvement in fracking regulation, and summarizes state legislation that is being developed to address environmental concerns.