Cheyenne's Big Boy Steam Engine is a reminder that the city was built on rail muscle. The massive Union Pacific locomotive on display is one of the largest steam engines ever constructed, designed to haul heavy freight over the Wasatch grades.
Even if you are not a rail enthusiast, the scale is impressive at close range. Pair it with the Cheyenne Depot and you get a compact lesson in why this high-plains capital exists where it does.