Ive been looking at flying thereabouts in late Sep. for the last few weeks. Its very hard to fly into the general area of Yellowstone for a reasonable fare - UAL sure are making a killing to Cody, WY
flights to all points in Montana are very pricey, no-lease-payment DC-9s or not! AA
only do ORD
-Jackson Hole in Winter so the closest i could get was Billings, Montana via LAS
for the end of September which is indirect from BOS
but oh well...il just have to drive!