We were standing below a rock, to the west of the exit of main chute. A skier from a different party had traversed out to skiers left of the rock and had made a turn when the snow released from the rocks roughly 30 feet above him and carried him about 150-200 ft below. the avalanche continued on another 300-400 ft below him. We were able to keep an eye on him until he stopped and the avalanche continued past him. We checked with him and he was okay- no visible injuries, just shaken up a little. Looking up on the slide from below, we could see that the avalanche had propogated roughly 100 feet or so across the slope to the west, which was nearly all in the scrub pines We observed other much smaller slabs throughout the Baldy shoulder terrain, and the theme seemed to be same- heavier, wind loaded snow sitting on top of a crust and facets, which collapsed fairly easy.
This slide occurred while Alta Ski Area was not open yet for the season.