I have a dim memory of the last major trail rebuilding on the switchbacks - I think it was in the late '90's. I believe the first year the trail was completely closed on specific dates, and the following year there was the possibility there might be delays. The first year I planned my trip around the dates, and the next year I had to plan the hike around the delays.
A general comment on glissading from near the top of the last(first?) switchback - the slope curves slightly to the left (north), so it's prudent to move a couple of hundred yards east (away from the crest) before beginning the glissade to compensate. Otherwise, you can be "drawn" into the rocks/boulders, and if you don't watch your speed, with possible disastrous results. Also - because of its exposure - it refreezes relatively early in the afternoon, and it's NOT a slope you want to slide on if it is icy/hardpack.
