Columns in Yellowstone NP

[MojaveGeek]

Those are cool.  I did not notice them when I drove by but I have not been in that part of Yellowstone in a decade - even though I spend much of a month in Bozeman each July, the national park is too crowded for my taste by then.  There's a lot of volcanic features around, and tons of petrified wood north and west of the park in the national forest.  And did you go up Specimen Ridge, where there are a few standing petrified trees?  Blew me away.