I lived in SW MN up until the last 4 years, and I have to say that the Bighorns would probably be your best bet in march. There is so much riding to be done anywhere that you won't see but a fraction of it in one trip, and the horns are more forgiving if bad things happen, and avalanches are pretty rare.
The scenery in Togwootee/West Yellowstone is amazing, and the area is much bigger, the photos of that area are better if that's what you're looking for. The tail system there is second to none. Lots of guide services available as well. Services at Togwootee Mtn lodge were amazing, new ownership now, we'll see how good it is, mechanics helpful, awesome outdoor hot tubs that feel great and some of the best food anywhere.
Second best scenery is in the snowy range, but as mentioned above, the weather gets downright nasty there, winds come up from nowhere and suddenly, you're in a blizzard and can't see well enough to even see the trail. Tons of good riding here as well, some prety extreme hills on the backside, and some really nice bunny hills on the east side, not far from snowy mountain lodge, the little hills there are great to get used to shooting up steep hills although you'll just about never get stuck on the hills. Mountain Meadow Cabins is really nice, but always booked, the snowy mountain lodge cabins are kinda rough, and no running water unless you are in a big cabin, I don't really like staying in laramie and driving, it cuts about an hour off of ride time by the time you get up, dressed, drive and get sleds ready and get out on the trail from laramie.
The bighorns are my favorite place to ride, the area isn't as big as Tog, nor as extreme as the snowys, and they don't get quite as much snow, but it's close, if you figure drive time, you will spend a whole day of additional driving (to and from) going to Togwootee, and another half day driving if you're going to the snowies. I'd rather be riding. Bear lodge is the place to stay at in the northern horns, great location, and great sledding from there, it does get a little beat up from too many sleds sometimes down 14A for the first few miles, but it's still NOWHERE as beat as the MN/Wisc/MI trails are. NOt nearly as many people out here.
Black hills are hit and miss, lots of people love them, you can usualy ride, but it's more confined, not many bowls or climbs, lots of exploring to do though and that's fun, if you can only get away for a weekend and wanted to go west, I'd go here if the snow was good, unfortunately, lots of people hit the hills trails right after storms and the tails get pretty beat, pretty quick, (similar to Two Harbors area, slightly more traffic, not as bad as Ironwood though) and the snow disappears quicker here in march. Lots to do, and eat, $15 all you can eat prime rib and king crab buffets are tasty at a couple of tha casinos.
Hope this 'book' helps, PM me if you have any questions.
