Enduring the coldest temperatures of any state in the U.S., Alaskans consume more energy per capita than anywhere else in country. Alaska is the second-ranking oil-producing state - second only to Texas - and remains a leading U.S. source of crude oil - ranking third in both crude oil reserves and production The North Slope contains roughly ten billion barrels of oil, while the National Petroleum Reserve - Alaska is the largest oil field in North America.