For moving heavy trains through the mountains, each railroad approached the challenge of building powerful locomotives differently. The Union Pacific's approach was quite straightforward; get as much as possible out of just one engine. Although not at all flawless, the engines that emerged from these trials and tribulations would go on to become some of the best known in the world.

To continue to see updates, photos, and new videos from High Iron, including San Juan Branch Line, follow us at these links:
Patreon:   / highironvideos  
Facebook:   / highironvideos