oil production

The oil boom in the United States is creating another boom — for the railroad industry.

So far this year, in North Dakota alone, 140 million barrels of oil have left on trains. Shipments of crude oil by rail are up almost 50 percent over last year — and this upward trend is expected to continue.

A visit to the world-famous Tehachapi Loop, part of a winding mountain pass in Southern California, demonstrates the scale and reach of the oil boom in the middle of the country. As a train full of oil tanker cars rumbles past, it's hard not to think of it as a pipeline on wheels.