I ran it this last August. It was pretty fun. If I remember correctly there are 27 switchbacks climbing up the mountain side. The width of the trail isn't the best but very easy as long as you pay attention. Out of all the switchbacks I'd say 10-15 of them require a 3 point turn with a 4 door and maybe 5 of them require more than a 3 point turn. Once your past the switchbacks it's a pretty decent trail. I think it's about 27 miles long from the bottom trail head to the top trail head
I ran it with the Magic City 4x4 club (fb) out of Billings, Mt and it looks like they plan to run it this year on the 25th of July. I'm sure they wouldn't have a problem with you joining them. I haven't decided if I'm going to do it again this year.