Send a PM to Rich Phillips (RichP) - he's the volunteer ranger down there opening up the station and will probably be in a position to pick it up if he does a run through the canyon, or have the next party going through look for it. You may also want to post this to the Utharafters-dot-com email list.
Good luck getting it back,
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse