Hidden Basin Loop Professional Review and Guide
"The Once you’ve entered Bear Pocket, keep to the left of the stream and follow game trails through rough, but not impassable, country. The canyon broadens and the view opens up as you gain altitude. Bear Pocket has a very impressive wall at its head, but you can get around it by taking the right fork as you approach the wall. Then pick your way upward more than 1,000 feet to the pass at just over 11,000 feet and 3 miles. From the pass, the view of the Shoshone Plateau to the north is glorious.
You can easily climb the mountain to your left (west), but the only route down is directly on the other side of the pass. A prudent person would bring an ice ax and crampons because a steep snow patch lingers late (pretty much all year). The main route drops into a cold-looking tarn 300 feet below. Once down, hike over near timberline and past a small lake until you reach Hidden Basin and the Cougar Pass Trail at 5 miles. Fill your water container at the springs here, because once you leave Hidden Basin it is many waterless miles to Twilight Creek."