J-tree wind is LEGENDARY in the climbing/camping worlds - many a lesser tent has met its demise in those campgrounds. It's not uncommon to see a tent, completely full of gear, including some pretty heavy stuff, blowing across the plain like a tumbleweed <img src="/ubbthreads/images/graemlins/eek.gif" alt="" />

All this is second-hand, unfortunately - I haven't gotten a chance to get to the park yet, but it's on my ticklist.