What is the most scenic route between Great Falls and Billings that you can do in one day? Thanks for the help.

I don't think there is one. I have driven it a couple of times. Just Montana plains, up and down through the arroyos.
Not many trees to speak of.

Bob Brown is right. There isn't much of a scenic route. Although, travelling through Judith Gap and the wind farm there is sort of surreal.

Oh well, it looks like I will just choose the fastest route and take a nap while my husband drives

Make sure that you have the sleeping figured out correctly! That road can be sort of boring, which calls for coffee.
320 miles, and a little over 3 hours.

Just don't believe all those 70 mph speed limit signs. I would not drive 70 on some of those roads, I don't care what the limit is. Years ago, Montana had no speed limit! Reasonable and proper. Out in the wilds, there is no de facto limit except on rare occasions.

I found it amazing to drive on a straight road (at whatever speed you want) for what seemed to be forever and then arrive at a 4 way stop. And, at every 4 way stop, there seemed to be a bar. Antelope and bars - all I ever seemed to see.

OOPS Make that 220 miles. Slight finger slip in a very significant digit.

Montana is a lot of land area, but Billings - Great Falls is not quite THAT far!

Now Whitefish to Hammond is another matter. 675 miles

And there is a four way stop at Eddie's Corner -- not really a bar, just a gas station and convenience store.

Do check out the windmills; they're huge and there must be over a 100.

Take hiway 3 to 12 to 89.

70mph is the limit. Anything under 65 you'll be holding up traffic so please pull over and let us pass!!

When you finish with Great Falls, come on out to Flathead county for some truly scenic views.

No speed limits - being from Atlanta that will feel like home - I think it has something to do with not moving during rush hour, when you finally can move you just go crazy We are actually starting out in Billings to Helena, to Missoula, to Big Fork, Glacier Park, St. Mary's, then Great Falls and back out to Billings - all in one week. It's blazes hot down here for the past few weeks - can't wait to cool done next month in Montana!

Although portions of the most direct route have additional route numbers the entire route is designated and signed as Montana 3.

Another longer alternative is to continue east on Montana 200 at Eddies Corner rather than turning south. That would take you through Lewistown, which is a nice city with numerous restaurants, and over a small pass to Grass Range where you could turn south on US 87 through Roundup on the way to Billings. More forested areas, less truck traffic, and more interesting terrain than Montana 3.

We stayed in Lewistown a few years back, the motel office was also a gun shop. Even the card they stapled to the motel receipt stated this fact. .

Slow down and enjoy your trip between GF and Billings. All of the "Big Sky State" is scenic,

Hope it's cool when you get here. We just finished 23 straight days of above 90 degree heat and 3 days over 100.
However the humidity isn't anything like Atlanta.