I have never seen roads as bad as those around Glacier.
Many years ago, drove out to a streetrod meet in Kalispell, then into Glacier, over the top, out the back, around, and back over the pass.
Broke a front sway bar link (ripped it clean out), BADLY chipped a windshield, chipped paint on nose, but, hey, that's the cost of doing business!
Apparently, Montana really likes to oil the roads and lay rock in the oil.
When they do that, just stay someplace else until everyone else has a chance to zing the rocks and splatter oil on the undercarriages.
Once all of that is done, roads are........passable.