they’d need to excavate 8 cubic kilometers or more.
that’s 22x the biggest project by volume – Maasvlakte2, Rotterdam, Europe’s biggest port. and that was sand not blasted rock. the cost would be astronomical
for comparison; Surez canal latest addition cost 9 billion for an excavation with a max altitude of 14 meters above sea level, over a stretch of 35km, while that mountain ridge is over 400-600 meters in elevation over a 40km stretch
you have no sense of scale.
a pipeline is much more likely; oil or natural gas.