The Bakken shale region marked a major milestone last month with production of its 1 billionth barrel of oil from the formation that spans portions of western North Dakota and eastern Montana.

A billion barrels is an extraordinary number, especially coming in such a short time. Keep in mind that just a decade ago nobody would have predicted such volumes of oil would come from the region, not to mention the economic transformation that followed. So that’s a billion extra barrels to keep markets and consumers supplied with needed energy that nobody 10 years ago thought would be available.

Much of this transformation has occurred in North Dakota, which accounts for the bulk of Bakken production, but not all. The economic benefits of Bakken shale energy are widely dispersed, flowing throughout the entire country and even benefiting states where there is no oil and gas production.

One of the most interesting statistics in this Associated Press article puts this billion-barrel achievement in historic context by focusing on North Dakota’s experience:

North Dakota began producing oil in 1951, when crude was struck on a wheat farm near Tioga in the northwest part of the state. The state tallied its 1 billionth barrel of oil in 1989 and the 2 billionth barrel in 2011. The state is on track to tally its 3 billionth barrel of oil this year or next.

Think about that. The first billion took roughly four decades to produce. The second billion took only half as long, and almost all of that oil was produced from conventional formations.

But the third billion barrels, which is coming largely from shale formations? That will take only about four years to produce.

It’s just more evidence of the extraordinary nature of the energy revolution currently underway in the United States and the benefits it provide.