The Golden Spike observation tower at Bailey Yard is easy to find if you follow the map in the North Platte visitor guide. Otherwise you may be driving around a bit. The tower is at the end of some roads that run just between fields, so until you actually see the tower ahead of you, you'll probably think you're heading in the wrong direction.
If you own high-powered binoculars, this is the place to have them. Even with an 8-story tower, looking over this 8 x 20 mile facility can be daunting. Some coin-op distance viewers are available. My 15X optical zoom camera came in pretty handy.
Train buffs and people who enjoy those mega-engineering type cable TV shows will enjoy this facility the most. Railfans need to make sure and also see the small but excellent UP train museum in Cody Park.
Hailing from Omaha which is Union Pacific's HQ city, I've gotten pretty fond of some excellent train/rail museums both in Omaha and nearby Council Bluffs, Iowa. I think this facility would be phenomenal as a more complete train museum. Some interactive displays, railstock, etc. would be great to make this a more complete experience perhaps even firing up the interest of the members of your party who are just along for the ride. As it stands now, it's just the tower itself, a few sparse displays at ground level, and a gift shop. There's certainly no lack of space should they choose to expand.
A special thanks to the guides at the top who were extremely informative and friendly.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.