Steve:
Thanks! Thats an interesting suggestion. May be I can check with Ranger station and start on July 14th afternoon itself and do 4 or 5 miles on the HST. Are there any streams/ springs around 4 or 5 miles into the trail from Crescent Meadows where I can camp? Still checking the NG map for spots.
Mehrten Creek is at just about 5 miles in. Campsites with a bear box are a short, steep climb above the trail, with great views. Much better acclimation than at Lodgepole, too. From there you could get well past BP the next day, up to Hamilton, or even better Precipice Lake, if you can do the 2000 feet late in the day. Either choice will put you well ahead of your pace for the cabin the next day.
