What size snowboard should i get if I wanna ride backcountry in Alaska?

If you weigh 180 I would suggest a 160cm board for all mountain riding. For a pure pow board go for about 165-167. I would suggest the Capita Charlie Slasher for a powder/backcountry board. I would also suggest the Lib Tech T-Rice banana hammock, but this is a powder ONLY board.

whats your weight? height has very little to do with getting the right size

if all your gonna to is ride backcountry pow and helli board check this out:

http://lib-tech.com/snow/snowboards/t-rice-banana-...

its travis rice's backcountry pow board. its not really good for anything else but its great for what your gonna be doing

edit:

you should probably look at getting a larger board for the pow and just riding in general. 155 is small for your weight, for pow only you could ride anywhere from 160-166 or even higher...for riding on the mountain something around 156-161 will work depending on the type of riding you want to get out of the board

Have you checked out sites like Burton? They let you choose your height, weight, level and what you will be doing with the board. You put in info it computes the answer. Even if you aren't looking to buy a burton maybe it could send you in the right direction.

i dont know