Right. The property straddles the old Barrets Tunnels (x2) which pierce the west side of the ridge separating the Meramec and the Des Peres rivers' watersheds. It also includes the old Barretts Station (though not in its original location). The tunnels were an operating headache for the MoPac from 1850 to WWII when the double track bypass just to the north of them was cut. among other things, the tunnels limited things such as cab hieght and sand dome size on MoPac Steam.
When the paralleling Frisco suffered a wreck and ran their trains over the MoPac main while clearing it, they had to reassign locomotives on many trains because the thoroughbred 1500-class Mountains were too tall to fit through the tunnels.
Joe Collias, chronicler of both roads' steam power, refers to the tunnels as "among the more permanent" exhibits of the museum 
Originally Posted by Hot Water:
Originally Posted by fredt:
Just curious as to why the first part of the trip was made as part of a UP train? Was that because they were on UP track?
Yes, the St Louis Museum of Transport is on the UP, at Kirkwood, MO (former MOPAC main line as I recall), thus the UP had to switch the NS consist into the museum, pick up the 2156, and then return to the NS terminal in St Louis.
