I triggered this nasty slide from lower angle terrain above I was skiing ~28 degrees. I saw the horizontal cracks cross the entire slope, immediately stopped and watched the slide pull away from me through trees then down into the main line all the way to the bottom. In the 13 years I have been skiing this terrain, this is the largest slide I have seen on this slope which tells me our snow pack is very different than we are used to. It's weak Colorado style snow pack with huge facet holes all over the place, powder and hard wind slabs all next to each other all within a stones throw. On my way down the flanks I discovered a huge 350ft wide sympathetic slide, same depth and weak layer...the facets that formed in December during our high and dry spell. Total width of the two slides combined, ~850 ft. There was about 50ft of un-moved snow between the two slides.