About 12 years ago I was with a group and we did the Potato Ridge from the back side. We started up Lovell Canyon Road from Blue Diamond Hwy. about 5 miles West of the summit at Mountain Springs. We then took Rocky Gap East into Red Rock. We entered into Red Rock at the picnic grounds about halfway into the loop road. Somehow we missed the toll booth completely.
It was a pretty easy run with some stock Jeeps making it. The only problem I had was trying to climb one steep grade without the front hubs locked. Once the hubs were locked it was easy going.