You got the who, still waiting for the how.
To impose a permit/quota system, you will need a commitment from FS and a whole lot of patrolling volunteers.
There is already a permit/quota system, in place. How is that enforced?
The only change would be to add the dayhiker element to it. What's the big deal about that?
If overuse of the new trail is the problem, go to a paid reservation system like for Whitney, the infrastructure is already in place. Poof! Instant funding. And you can pretend that Wagbags are required and everything, If the use is not to that level yet, then what's the problem?
Build it and see if they come. Bet they don't, not without some promotion. Never done Langley, but it sounds like a lot more fun as it is than with a trail. And for that matter, a lot more fun than Whitney.
Probably the solution is in marketing rather than in building the trail. Diminish the pressure on Whitney by diminishing the appeal. Create a new Whitney - Langley Zone, promote Langley on its own merits: a little class 2, maybe some 3 lots of different approaches, etc. When you get down to it, aside from the abstraction the Whitney is the higher, isn't Langley the better experience?
