Northern Nevada Railway
The best part of traveling on a flexible itinerary is coming across a surprise gem. The Northern Nevada Railway in Ely is one such gem. For Nevada, I use an wonderfully comprehensive old edition of the Nevada Moon Handbook which pointed me to the railroad. The railway and museum is an entire operating train yard that feels like it's been transported 80 years through time. The engine house is still a working building that keeps the railway's locomotive running. Visitors are able to explore than the entire engine house on the own. Industrial era shops are great photo locations and being able to explore a working period shop is a rare opportunity.
If you are a fan of steam rail, the Northern Nevada Railway is a must see. It's the only intact period operating steam yard in the US. The rail yard feels like the workers just put down their tools and left which is essentially what happened when the copper mines closed down. Because Ely is so remote, the land wasn't redeveloped and the mining company who owned it was persuaded to donate the site and the equipment to the state of Nevada who turned it a museum. Although it's hard to get to due to it's remote location, I'm sure I'll be back to visit again, maybe for their Winter Photo Shoot Weekend.