From:
https://volcanoes.usgs.gov/volcanoes/yellowstone/yellowstone_sub_page_91.html
Well, at least most of the old Illinois Central wouldn't be affected if a major Yellowstone Caldera eruption happened today ;)
Really have to wonder what kind of contingency planning if any BNSF and UP have done on this eventuality. Obviously ash removal of any kind from the RofW would require a huge fleet of equipment and manpower.
Living here in Helena, I guess I would have a front row seat to the action. At least we are not in the Yellowstone River Basin to the east which would be a major conduit for a Lahar type event. Actually, I worry more about a nuclear attack on Malmstrom AFB in Great Falls with all of its ICBM silos.