>>2235188Not exactly hidden but Hansen’s point has some of my favorite backcountry camping sites I’ve seen, and the spot on its own is beautiful (pic rel, me).
Martin’s Fork —> Rough Trail is a great loop that doesn’t see a ton of traffic, and lets you take a detour to grey’s arch. That’s one of the more tourist heavy spots but not from that trail. If you make friends with climbers at Miguel’s, they can show you some of the better backcountry spots hidden around.
It’s honestly hard to recommend specifics without knowing what you like because there’s so much to do there, it’s like top 5 in the world for diversity of climbing and you can do anything from a two mile to 18 mile hike in a day. Pretty decent kayaking too.