There is No trackage left in Wallace ID, only a trail. The UP came into Wallace from the west, at Plummer ID. The NP (later BN) came in from the east, over
Lookout pass. MILW's
St. Paul pass is SOUTHEAST of I-90's and the NP's crossing of the Bitteroot mountains at Lookout Pass.
When BN abandoned the ex NP line in 1980 the UP took over the BN trackage from Wallace to Mullan to continue serving the mine in Mullan.
When UP pulled out in the early 1990s the whole 72 miles from Plummer ID to Mullen ID became the "Trail of the Coeur d'Alenes". Here is a link:
[url=http://wallace-id.com/CdA_trail/]
The MILW line is east of Lookout pass. It comes out of a canyon from the south at Taft MT (exit 5 on I-90) where it is still high up on the hill above the interstate. The trailhead for the "Route of the Hiawatha trail" is 2 miles south of Taft. This trail goes through the 1.7 mile long tunnel UNDER St Paul pass and continues west into Idaho, terminating at Pearson ID. Here is a link:
[url=http://wallace-id.com/skilookout/taft.html]
Here is MILW box-cab E34 in the siding at Falcon ID, taken August, 1957
The BN (ex NP) Wallace branch ran on the MILW west from St. Regis MT (I-90 exit 33) to Saltese MT (I-90 exit 10) where it regained it's own right-of-way over Lookout pass and into Mullan and Wallace. Much of this old ROW is close to the interstate and can be seen from the interstate.
Ironically the MILW quit running in March 1980 but BN continued to operate into Wallace until September 1980, making the BN the last operator of the MILW St Regis - Saltese line segment.
Hope this clears some of the confusion.