We understand this wedding format is different from what people are used to and deciding what to pack/wear to a wedding can be stressful especially with such a unique format. If I were attending this wedding as a(n)....

Adventurer

Ceremony: A nice dress or nice button down shirt and pants you want to be photographed in

Adventure: any attire that you can comfortably do your chosen adventure

Dinner: the same thing you wore to the ceremony or something comfortable that you want to be photographed in

Post dinner: maybe a bathing suit since there are hot tubs at most of the lodgings. Post dinner plans will be made on the spot. Keep in mind at night in the mountains it can be chilly.

Hang outer

Ceremony- A nice dress or nice button down shirt and pants you want to be photographed in

Dinner- A nice dress or nice button down shirt and pants you want to be photographed in