Remote Triggered slide at 'The Notch'

Dropped down the main entrance to the riding area on the South East side of the pipeline with four snowmobiles. Riders proceeded one at a time...when the third rider was halfway down a remote slide was triggered approximately 75 meters to the north. This was an East facing slope and the failure was on crystalline snow approximate 70 Cm deep. The slide was approximately two hundred meters wide an ran for approximately 100 meters.