What kknowlton said.
However, the Bighorns west of Buffalo are very pretty, and as mountain roads go, Hwy 16 is a piece of cake. My wife doesn't like mountain driving (or riding), but as long as we stay on Hwy 16 over the Bighorns she doesn't mind them a bit. We go there often. Now some of the Jeep trails... that's another story. ๐
Actually, if you don't mind the roads in Yellowstone, and you don't mind the mountains between Dubois and Jackson Hole, you shouldn't mind 16 from Buffalo to Ten Sleep either. It's easier than many of Yellowstone's roads, and I'd encourage you to try it. The highway is wide and well maintained (4-season) all the way across, and you'll only have a handful of curves that you can't safely take at 45 mph or better. Traffic is always fairly light, and there's plenty of places to pull off and enjoy a picnic or camp for the night.
There's a 5 or 10-mile climb coming out of Buffalo, then it's all gentle curves and easy hills across the mountain until you enter Shell Canyon on the other side. That's another 5 or 10-mile descent to the bottom with two 20 mph (iirc) hairpin curves towards the top of it (just after crossing Shell Creek).
As with all mountain driving, use a lower gear when descending rather than depending on your brakes, which can overheat if you "ride" them. If they overheat, you suddenly lose all braking. That's not fun.
