Canyons are inherently risky. Flash floods occur without notice on sunny days. Technical skills & surrounding topography knowledge required yet does not eliminate risk.
Overview: A beautiful forested and pool-filled canyon, hidden deep below the soaring granite walls of Clouds Rest and Mount Watkins. Miles of rock hopping and boulder scrambling, with four rappels up to 70 feet from bolted anchors. Best in late summer and fall, the inner gorge would be impassable at high water levels.
There are two approaches: 1) follow the outlet of Tenaya Lake, descending the steep slabs south of Pywiack Cascade or 2) direct descent from Olmsted Point to the base of Pywiack Cascade via a steep, brushy gully. There are also two exits: 1) climb back up and out via Snow Creek trail or 2) continue down into the Valley and car shuttle back to the start.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.