Pywiack Cascade is a seasonal waterfall on Tenaya Creek in Yosemite National Park, near the outlet of Tenaya Lake at the head of Tenaya Canyon. Instead of a single vertical drop, it descends about 600 feet by sliding steeply over solid granite, with a smaller fall below and additional cascades farther downstream toward Mirror Lake and the Merced River. Fueled mainly by snowmelt, it is strongest in spring and early summer and often shrinks to a trickle by late summer and mid-autumn. The name, pronounced “Py-we-ack,” comes from a native word meaning “glistening rocks,” referring to the polished stone of the upper Tenaya basin.