I'll be travelling from LA to Las Vegas in mid August as part of a 3 week backpacking trip. I would love to visit Joshua Tree en route - maybe do a bit of bouldering and camp overnight (I realise that it will be very hot at that time). The major problem is that I can't drive so will be relying on public transport. Does anybody know of any company that does overnight visits to the park - maybe from Palm springs?? i could then organise the rest of the journey independently. Thanks for your help.