Thanks for the comments everyone. It is beautiful country that's for sure.
I'm sure it would take a lot of time running it in a full sized vehicle. It gets pretty hairy running a regular ATV on it and coming down I had to actually back up a few times to make some of the switchbacks. I don't think I would want to take my Polaris Ranger on it.
Running the ATVs up it wasn't bad though. Probably took around an hour and a half from the bottom all the way to the top. Getting from the bottom to the bench was the worst I thought although some I've talked to say from the bench to the top is the worst. Going up wasn't bad at all to me, maybe even fun, coming down wasn't fun, I'm not sure I want to do that again unless I really need to.
Kind of a crazy world the way things work out, my friends son who lives in Powell just got a new job and his first day of the job was taking a mini-excavator to the Morrison Jeep Trail to do maintenance on it. I would NOT want to run a mini-excavator up and down that thing! He had a track come off twice and after the first time had it figured out that you always need to be running with the blade pointed downhill. He said he was pretty much told not to make it too nice, just move the biggest rocks out of the way and fill in holes that are more than 12" deep. He said the guys at the switchback ranch run full size UTV's on it pretty regularly, I think going up wouldn't be bad, but for sure wouldn't want to run down it on a UTV.