Quoted By:
Fuji X-T10 (or T20 now). Mostly I use the cheap kit lenses when i'm hiking since they are so light but if i'm feeling good i'll bring a prime or two with for more composed shots. Pretty light setup and easy to carry on a strap or just fit in on the top of your bag.
I've had better DSLRs but wouldn't bring them with due to the weight/expense so the fuji was my solution, any mirrorless will fit the same requirements though just find the one you like. If you need smaller than that the sony rx100 works pretty well but i like the option of switches lens for whatever trip.