North Cayoosh. 2.5Na Rock and Roll SW aspect

Sz 2.5 natural off SW facing slopes off Rock and Roll ridge dumping into and filling up part of Cayoosh Creek N. Snowpack failed to ground. Didn't check failure plane. Pictures and monocular showed 5 (perhaps 6) failures starting with glide crack then stepping down successive layers culminating with failure to ground. Crown was at approx 1900 running to 1500m to N Cayoosh Creek entraining small trees and rocks. Searched debris for beacons transmitting with nil results. On our way up from valley floor we had handsheared the snowpack while in trees finding 30 - 40cms of low density fist snow overlaying a finger layer with a melt freeze layer between 40 - 60cms down. Reasonable inference is that the snowpack failed on a persistent weak layer (MF at lower elevations, decomposing facets at higher ). Temps - 6. Winds light, SW from ridgetop. Skies clear with high clouds towards end of day.