I make that trip frequently (we have a daughter and SIL and three grandkids in Great Falls), plus it is the nearest commissary/exchange.
I usually take 87 to Eddie's Corner, then 191 South to Harlowton, 12 to Lavina, and State 3 to Billings. I have done it in our Class A, towing the Jeep. No problem.
By the way, it is Lewistown in Montana. I think Lewiston is in Idaho.
CM1, USN (RET)
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