American history has been driven by transportation. Bicycles, automobiles, airplanes and -- of course -- railroads allowed commerce to fuel the development of history's greatest economic dynamo. Rails were standardized hundreds of years ago, but the standard gauge, or any other gauge, wasn't effective in the mountains of the American West. So, in this episode, we take a ride on the Durango-Silverton historic railroad and talk to the engineers, guides, and experts about why and how this innovative technology was created and how its short but glorious lifespan effected the conquering of the American West.