I guided the South Face/regular route of Grand Sentinel Yesterday August 8. The reg trail that traverse to the spire from Sentinel Pass goes underneath couple gullies that has lots of snow and ice, and poses lots of rock fall hazards. It is much safer to descend from the pass all the way down and head up to the grand sentinel staying close to it on the right. Lots of rock fall happening yesterday!
While I was starting the 2nd pitch there was a party of 4 and a member got nailed by a rock. I think it hit their knee, but seemed like they were able to hike back up to the pass. One thing for certain they were extremely lucky. These rocks were big enough that it could kill you.
Play safe out there,
Marco Delesalle - Mountain Guide