For me, it's a lot of things. While this summer will be my first summer carrying lots of heavy gear, I've taken backcountry photography seriously for a while now.
First, it was to capture memories - I've never wished I'd taken less pictures, always more.
Then, I started to get into the artistic aspect of it, enjoying positioning myself, framing a subject, and setting up my camera correctly, the same way a fisher might enjoy finding the perfect spot, picking the right lure, etc.
And recently, it became part of my work, taking pictures both for myself and for the newspaper I work for.
All in all, photography is just one means to an end for me - sharing an experience or telling a story to expose others to things I enjoy.