Yes thishad a considerable thread on Pprune - it was an intended trans-Atlantic flight and the aircraft was either an Arrow or Cherokee 6 - so a much more capable Cherokee.
But this was flying in very poor weather and then going IMC into cumulus granite.
Flyingin the mountains is not difficult. Some caution is necessary but otherwise it is straight forward. Winds over 20 kts will make life very uncomfortable and if you hit the rotor off the back of a hill will roll over even heavy aircraft.
Stay VFR and be prudent with the wind and there are not particular problems. Learn how to land on steep hilsides and the number of landing spots increases very significantly. All you then need is some decent clothing so you can potentially walk out.
I do it most weekends and many of the warnings are of the 'here be dragons' ilk. Understand the weather and where the cloud will build and it is a tremendous place to fly.