One of the most famous, perhaps the thé most famous, inbound couloirs in the US of A can be found in Jackson Hole. Corbet's Couloir is marked on the slope map and then you might think 'it's on the map, how hard can it be'. Yet a lot of people go tomahawking sown. Corbet's was first skied in 1967. A great movie of Todd McScraffy and Biff Huckneck!
In 1992, I saw a report about Corbet in the Onboard (magazine) and then figured out I'd like to ski that once. 19 years later, it was time and I could cross Corbet's (without tomahawks) off of my personal ski bucket list.