North Sister, Early Morning Couloir. I made a solo ascent of this couloir. This fall the record lack of precipitation and lower temperature offered unusual possibilities. At 1:30 on December 20, I left the lower screes and progressed quickly up this 1500-foot couloir. The first part was good footing firn and then medium-hard ice in the steeper mid and upper sections. The final traverse onto the north ridge was tricky due to slab ice. I made a hasty descent down the northwest face. The ascent took one hour.