Soft Slab/Wind Slab avalanche was trigger by a snowboarder. This slide occurred just to the South of the saddle that leads up to 10420. This is named "Hidden Canyon Saddle" on the Achilles Map. This is near the area where the usual boothike out of Lacaxen is placed. This slide was 80 feet wide and ran 150 feet. The aspect was NE, the slope angle was at least 40 degrees, and the elevation: 10150. The terrain was a sub ridge that separates the basin where the boothike is to the next drainage to the South. It appeared that the rider hit a thin part of the slab on the top of the ridge. The rider appeared to punch it and run past the slide and escape. The crown was 3 feet. and the weak layer appeared to be a thin 2 mm layer of facets that formed directly on top of the old snow surface interface from the beginning of this last big event that began technically on Friday/Saturday. There was at least 18 inches of fist and then 18 inches of 4 finger. The prestorm surface (bed surface) appeared to be wind board, and had a slight m/f frozen snow cone like crust texture that I am assuming came about from the mild ambient prefrontal temperatures.