Pacific Northwest slang for climbing up to the roof to get high.
Dude 1: "Dude, you should have been there last night, we climbed Mount Ranier
& the view of the stars up there was magnificent."
Dude 2: "Aw, man, next time I'm climbing with you!"
Dude 3: "Why are they going upstairs?"
Dude 4: "Oh, they're Climbing Mount Ranier."
Dude 3: "Why do they never invite me!"
Dude 4: "Cuz you're afraid of heights, Dude."