Cliff collapse commonly initiates a sequence of rockfall events over a time span of days to years. Wieczorek and Snyder (1999) nicely document three such events in 7 months above Curry Village in Yosemite valley (Fig. 7). None were earthquake induced. The first rock fall from the cliffs below Glacier Point was the largest, about 1576 metric tons and may have been triggered by seepage forces generated by ice that plugged the fractures to raise ground-water levels. The block(s) fell 30 to 45 m down a 75° cliff face to a ledge, breaking up against the cliff, then fell another 290 m before hitting the top of the talus. Block size and velocity was sufficient to remove large trees. Huge prehistoric rock-fall blocks partly determined the paths of bouncing blocks that crushed vegetation as they rumbled through the forest. Subsequent rockfall events followed the earlier routes. Some blocks traveled 500 m from the top of the talus, and small fly rocks may have been ballistic fragments that traveled much further from impact points high on the cliffs.