Agreed. It would be a challenge to string together 50 miles up there without retracing a bunch of footsteps. I've only done Middle Basin. Hiking up to that saddle west of Ryder gets you an amazing view of both sides. You can bag Hayden Peak from there. I plan to do it next time I get a chance to get up there again. Apparently there's a route that can get you into Middle Basin from Highline TH by going straight up to that same saddle from the west side that shaves a ton of mileage from the traditional Christmas Meadows TH approach. I'm hoping to hit up Naturalist Basin this June and get up on the ridge above there to have a look down into Middle Basin and see what a route in/out of Middle Basin would look like. If you could extend a loop going over one of those ridges from Middle Basin and back into Middle Basin with the other, taking in Naturalist Basin and Scudder lake in between, you could then probably get closer to 50 miles out of it.