No radio will give you miles of range unless you are using a repeater, are on a mountain top or on flat, unobstructed terrain. With that said, MURS will be your best bet for range in mountains, but the radios will be bigger and heavier than FRS/GMRS bubble pack ones.

Honestly, I would go with some small FRS/GMRS ones that run on AA batteries. While you may not always be able to contact the other group or groups, it is a good compromise between size, weight and usefulness. Yes, everyone should have a GMRS license to use the GMRS channels but if you stick to the FRS only ones no license is required. And while I don't promote it, I doubt you'd get in trouble for using the higher power GMRS ones without a license.

I'm not here to start the license/no license argument, just to give my thoughts on radios (and yes, I do have a GMRS license).