How about a wedding in a lodge setting and then do the backpack as a honeymoon? Or a wedding in the lovely meadow at Roads End, and then backpack.

I attended a wedding on the top of Mt. Shasta years ago. They did, however, have a reception after the climb at a lodge because few family member could do the climb.

You do not have to elope to have a small wedding. Just invite a few best friends and immediate family.

You get the paperwork done from the county you reside in, and then take the papers wherever you wed, and you must have one witness in addition to the person who marries you, sign the papers when the ceremony is done. My husband and I had a 4-person wedding - the two of us, his best friend who had some weird license to marry, and his friends wife. We did it all, when the spirit struck us the day of the "wedding", at his friends house, between tasting wine, dining and visiting.