Another way of saying "Middle Of Nowhere", generally implying a negative tone, and the Idaho reference because the state is seen as boring. Often used if some one lives in a boring area or they got lost going somewhere.
Ex 1
Guy 1: Dude, where are you? You're late Guy 2: I took and wrong turn and ended up in Buttfuck Idaho
Ex 2
Girl 1: So you got anyplans for the weekend?
Girl 2: No, I live in Buttfuck Idaho
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2 million.