The author of this thread was just down at big tree and has some bits about getting there and conditions in that thread. Not sure about water!
I would not in a million years attempt a x-c hike to the tarn from big tree with a group of boy scouts (or any group for that matter).
People need to be aware that a lot of the “routes” on jim’s map are fanciful ideas, not tested routes. walking from big tree to the tarn is a trail-less route that gains 2000 feet in about a mile, which is twice as steep as the national park services steepest “standard” trail.
