The United States accounts for more than one out of every 10 barrels of crude oil produced around the globe each day, according to the U.S. Energy Information Administration. This is due in part to rising production of tight oil found in shale rock formations, but overall produced crude oil in the United States mainly comes from a handful of states and the Gulf of Mexico. Five states and the GOM supplied more than 80 percent, or 6 million barrels per day, of the crude oil (including lease condensate) produced in the United States in 2013, the agency reported. Texas alone provided almost 35 percent, according to preliminary 2013 data released in the EIA’s March Petroleum Supply Monthly. The second-largest state producer was North Dakota with 12 percent of U.S. crude oil production, followed by California and Alaska at close to 7 percent each and Oklahoma at 4 percent. […]