The states that are home to the most oil, natural gas and coal production have substantially increased their collective share of American energy output in the 21st century, concentrating production in a few key locations, according to the U.S. Energy Information Administration (EIA).

EIA Production

The six leading states — Texas, Pennsylvania, Wyoming, Oklahoma, West Virginia, and North Dakota — accounted for 55 quadrillion Btu (quads) of total energy output in 2019, the most recent year for which complete data was analyzed by EIA. That total was 55% of the primary energy produced in the country, up from 39% in 2000, the agency said.

The vast majority of primary energy in that span consisted of gas, oil and coal. Over the past decade, energy production in the United States grew 40%, driven...