To approach this route, begin at the trailhead at Glacier Lodge. After you cross the North Fork of Big Pine Creek on a nice bridge, you will switchback to the east, and then back west to cross the creek again. Shortly after that, the trail will give the option to continue south, or to turn to the north. Take the north option and follow the North Fork drainage to the Big Pine Lakes. After you pass 3rd Lake, continue on to Sam Mack Meadow. The trail ends here, and you will follow a small drainage that is oriented nearly due south. As this runs out, crest the current terminal moraine for the Palisade Glacier, and all should become clear as the Palisade crest from Thunderbolt to Mt. Sill will be laid out before you. Continue on to the right side lateral moraine, and then follow a tongue of rubble that leads just right of the bottom of the Underhill Couloir. This rubble tongue may not be available early season due to snow. In August, it was clearly evident. The entry into the couloir can be difficult as most of the slabs and ledges are covered with sand and very loose debris.
This description covers only the right-hand couloir, we did not set foot in the left-hand, but it is supposedly similar. When you're finally past all the rubble and sand at the bottom of the couloir, the climbing becomes fun and interesting. Follow the couloir to the top, usually staying in the bottom of the couloir, with occasional forays on to the side walls to circumvent chockstones. There is a large, fairly difficult chockstone at about 2/3 height, I passed it on the left, Scotty on the right, the difficulty seemed about equal, but be careful grabbing some of the blocks wedged on top of the main chockstone. At the top of the couloir, turn right (northwest), and scramble up some fun, fractured, 3rd class slabs. According to Secor, at the top of the slabs, there is a chimney just to the right that gives access to the summit ridge, but it was not evident to us. Instead, we went left, and climbed a short section (15-25 feet) of 5.5-5.6. It was very exposed, but the climbing was straightforward and we did not rope up. From there, it was 3rd class to the summit ridge, and 5.9 on the summit block. The summit register may or may not be on the summit. The location is a point of dissension among some peak baggers, and technically, if it's not on the summit block, it's not at 14,000 feet, as the top of the summit block is barely over 14, at 14,003'. Since this is informational only, that is all I will say about the location of the register.
Wear sticky rubber approach shoes for the whole route so you don't need to carry 2 pairs of shoes, and forgo the rope and light rack unless you're really uncomfortable with exposed 4th class The 4th class section is short, and is more scary (although no more difficult) on the way down. Early season will likely require axe and crampons to access the couloir. There is plenty of clean, pure water all the way to the bottom of the couloir, and you already know about the afternoon Sierra T-Storms. Start early, summit early, descend at your leisure.
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