North Sister, South Ridge

Activity Notes

North Sister is the most rugged and considered the hardest climb of the Three Sisters in central Oregon. It also could be considered one of the hardest of the Cascades volcanoes when comparing "standard" routes. It's the oldest and least climbed of the Three Sisters. First ascent was by H. H. Prouty in 1910 for which the summit pinnacle is named. Originally thought to be over 11,000 feet, it has eroded and is basically a large pile of loose volcanic rock. There are two pinnacles at it's summit and many gendarmes. There is also lots of loose rock and rockfall.<br> <br> Only the easier routes are often climbed. These include the south and southeast ridges as well as the northwest ridge. There are two main approaches: the Obsidian Trail approach from the west and the Pole Creek Springs approach from the east. The two south routes meet up and share the same final ridge. In summer conditions, the traverse to the Bowling Alley, the final summit pitch up a loose, steep gulley, is on a narrow, crumbly, loose rock ledge and the Bowling Alley is Class 4 junk. Under snowy conditions, the traverse is a steep side-stepping affair around a ridge and the Bowling Alley can be 70-80 degree hard snow or ice.<br>