This goes to show you HAVE TO be careful. I know most will not heed this reminder but here it is any why.
http://www.latimes.com/local/lanow/la-me-ln-student-jumps-dies-angeles-national-forest-20131112,0,7782398.story#axzz2kimqspUy
If this helps one rock jumper NOT get hurt, It will be worth it.