American oil producers are putting oil on trains more and more often to get it to markets that are underserved (or served at all) by pipelines. In this video, contributor Aimee Duffy explains what started this trend, which companies it affects, and why producers in plays like North Dakota's Bakken Shale may want to stick to shipping via rail for a longer time than some analysts think.

Motley Fool contributor Aimee Duffy has no position in any stocks mentioned. If you have the energy, follow her on Twitter, where she goes by @TMFDuffy.

The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.