Snowboarder traversing in hidden canyon yesterday triggers a slab that broke about 8 feet above him, he said the cracking spider webbed around him about thirty feet. Seemed to fail on old snow layer but easily could have been a wind slab from high winds. He was able to use his edge to anchor in and let it slide around him. Very small slide but with hundreds of people going through hidden canyon it could have easily swept someone or a group through the trees it ran through. This was the first of two small slides we started around brighton yesterday. A photo can be located if necessary.