Not sure where that information came from, most of the Pass is natural ie fill from graded ROW
and predates most of the heavy extraction in the Butte area. BNSF has always had strategic plans
for the PNW to Texas, the line is somewhere in the middle of some study. In reality the whole thing
rders on a Mexican standoff with the UP ownership of the line into Butte. Yes there's a long term
lease but you're now talking of some big time leasehold improvements to update the Butte-Garrison
section to handle heavier traffic not to mention the cost of reopening the Pass. One thing in the
line's favor that other than the short stretch over the top the rest is a piece of cake, power
wise.