woo...thats a long time.
well i guess if your in the mountains,they wont have a gym. bummer. if you absolutely have no equipment, heres what i think you can do.
chest/triceps:
pushups/1 hand pushups/pushups with a heavy backpack/pushups with someone on your back/clap pushups...you get it
back/biceps:
if you can find a horizontal tree branch, pump out some pullups and or chinups. just look around for any horizontal bar you can do those on
legs:
snowboarding i hear is pretty hard on the legs already. but still, i think you should try some one legged squats, you can do lunges while holding heavy stuff in your hands. maybe you can deadlift some suitcases...jk. you can do some sprints for legs.
shoulders:
handstand pushups or you can find some stuff to military press. like...i dunno a suitcase or something with phonebooks in them ><
i say do some of these things and eat very clean and enough. your diet will be important. otherwise, i hope you have a safe, very fun and relaxing vacation my friend