That one is news to me, and I live in North Dakota. Got a link/more info?
No I do not - but it was discovered many years ago while dino hunting - wiped out many in the area - was something on History or Discovery also. Will look around if I find more in my files I’ll post it for you.
Opps sorry it was Montana not ND - you can be safe now ...
77,000,000 B.C. - Elkhorn Mountain Volcano (EMV), Montana, U.S. (Super Volcano) Erupts
Covered an estimated 26,000 kilometres to a depth of approximately 4 kilometres.