Day 3 of my yet unwritten trip report:
This summer, I camped on the north side of Sky Blue Lake, after a very long day where I went from Cottonwood Lake 6 (northern most) to Langley Summit, to lower Soldier Lk, then to Sky Blue. Lost my cookies after dinner due to altitude and exhaustion. But it was a fine camp -- gravelly surface for my pad, and a flat hunk of wood for a seat, and flat rocks for my tiny Esbit Wing stove. Right at
these cross-hairs I think. It's pretty amazing to find such a well-beaten use-trail in such a remote place.
Rested well by Sky Blue. Next morning, I climbed northwest, then westward to avoid the steep approach leading to the next big lake. Reached the lake west of Sky Blue, then crossed over heading northeast, curving around to Crabtree Pass. Dropped down to the uppermost Crabtree Lk and continued on the north side down to the next Crabtree Lk. Walked along its sandy beach, took a quick swim, and ate lunch there.
I had some fun trying to find and follow the very old (unmaintained) trail from mid-Crabtree down. Lost it a few times, especially just below lower Crabtree Lk. But succeeded in following it all the way down to the point where it doubles back across the upper Crabtree Meadow. I continued west there as I wanted to head down Whitney Creek to an old horse-packer camp. I crossed the PCT well into the afternoon (maybe about 3 pm)
I probably could have made it to Guitar Lk, but then would have had trouble with dinner again.

But I'm old -- I've got 4 grandkids if that gives you an idea. If my previous day hadn't been so long, and I had planned on it, gotten an early start, yes, Guitar Lk would have been possible.
I had an interesting encounter that day: As I was wandering westward above Sky Blue, another lone hiker came along. He said he was "looking for a ridge" that a friend had described to him, where he could easily head back toward Rock Creek (or Soldier Lake, I'm not sure). Every so often he would pull out his iPhone and look at it -- some map app I guess. Said his friend had given him a gps track.
...Well, by anything I can read of the maps in that area, he was just plain lost! There are no ridges to follow to the south. Everything is steep and rugged, and the ridges branch east and west -- nothing smooth enough to be anywhere near "easy"! I'm sure he made it out, but probably back down the Rock Creek valley.
Another interesting encounter: A water filter and underwear hung out to dry by the creek below Sky Blue. But not a sign of a tent or anyone around. Odd, at least.
My camp by Sky Blue Lake

Sky Blue Lake the next morning. This picture makes it look much smaller than it is.
