Okay, from my "vast experience," <img src="/images/graemlins/tongue.gif" alt="" /> I'll recommend you consider a Sony ICF-S10MK2.

It's $10, Sony generally makes outstanding radios, and it compares favorably for distant AM reception with a $600+ ICOM R75. (See a review here.) You only need to worry about AM reception if you're in the wilderness; don't expect any FM reception unless you're fairly high up or near a major city. The radio weighs 7oz which is pretty good for backpacking, although some people might search for something lighter.

Also, if you're a ham, you should follow the Wilderness Protocol and monitor 146.52MHz on the 2M band. For the first 5 minutes of every 3 hour period starting at 7AM, many hams monitor this frequency for emergency communications. (It generally requires an LTZ -- a long tone zero via DTMF -- to get people's attention.) Some park rangers and police stations monitor this frequency constantly as well. You may want to ask at the ranger station if they monitor frequencies and if so, which ones. (Each VHF/UHF ham band has its own emergency frequency.) It's always nice to have a way to contact the outside world when your're out of cell phone range. (By the way, I should mention that you'd need a ham radio to do this, the above Sony is just a simple AM/FM receiver.)

Have fun and don't forget extra batteries,
Fitz