Last time I was down there, the road to the ranch was grated. It's not super well marked, definitely bring a map. Below the ranch, it was nasty. 4WD and high clearance for sure. I thought I heard someone say that they had fixed that section as well, but it's still pretty damn steep in sections and will get rutted quick. It took us a good 2 hours round trip once you turn off the highway.
I would try and connect with one of the commercial shuttles and see if they have any trips pulling out at Gleason the day you'll be there.