FATMAP difficulty grade
Wider and less steep at the top, this couloir narrows significantly before a cliff in the center, then it continues as a classic rock walled strait, and quite steep, couloir until finally opening onto an apron.
It is named Mandatory because it has a manditory air (or straitline?) in the middle.
A rappel over the rock requires setting up your own anchor.
Maybe this could fill in enough to go through on a huge year, but who knows?! See www.couloirquest.com.
The difficulty rating for this route uses the posted FATMAP criteria.