I've never done with lockers. Always open diffs. Still very do able that way.
I bet it was cool to be in the Needles and Island in the Sky before the crowds. Im from Wyo right next to Yellowstone and I often am envious of the mountain men that got to see all of this country before we all came in droves. The crowds there are next level trust me.
But we did go to The Maze and it is still VERY isolated thankfully. Was so cool I went back there just 2 weeks ago.
Makes me wonder what it will all be like in twenty years too..Public land could be a thing for the history books by then..