FATMAP difficulty grade
This is an extremely gnarly chute located on the backside of Black Butte.
Take the Black Butte Ridge hike and walk to the final chute.
You'll find Diagonal Chute here.
You must first down-climb into it (rope is absolutely required).
After you get to the gut of the chute, getting your skis on is an absolute pain, but once you do the skiing is actually one of the easier parts of the whole experience.
Granted the chute is extremely narrow and surrounded by huge cliffs.
Eventually you'll filter onto Black Butte Gully.
This is a brutal line that very few people even attempt due to its hidden nature.