Don't know if you noticed. Most folks don't.
Driving through Wyoming on your way to Montana is pretty boring (unless it starts to snow) and right about the time you get past Sheridan you may notice odd reflections in your windshield and maybe even the clock in your vehicle flickering.
No problem. You're just going through a time warp.
The actual end of the warp is right at the state border (if you look at that Welcome to Montana sign you might even notice it billow in the wind...only the wind's not doin' it) and about the time you hit the expansion joint there you've just turned your calendar back somewhere around twenty years.
Welcome to 1999, y'all.
Mind the instant headache you'll get on the way back.
/jk.....or maybe not
I was in Montana for 2.5 years... most of it winter!
My first week there, when I woke up, the guy on the radio said it was -39 degrees. outside.
I had no frame of reference for that.
A few weeks later, I woke up to hear him say it was 32 degrees.
Even before coffee, it hit me that the temperature went up 71 degrees and it was still freezing!