I have been wondering when was the last time a Class I laid 5 miles or more on completely new right of way that had not hosted rail tracks ever before? I am aware of much double tracking where a second track was added or relaid after decades of not being there, but how about completely new right of way? The 5 miles number is arbitrary, but I want to exclude minor extensions of which there are probably plenty. In the public transportation space the only one that I am aware of to has laid 5 miles of rail where no track has been ever before is Denver.
Probably the lines into the PRB in WY, or the Mt Macdonald tunnel in BC.
I could be wrong though...