I hiked up the Bobsled with Mark A. this afternoon to re-visit the scene of his accident. It was a bit unnerving walking uphill on a popular high speed, downhill-only trail. I kept expecting a rider to come flying around a corner but luckily we didn't run into (pun intended) anybody.
He went down just above where this car sits off to the side of the trail, on an off camber section of loose surface on top of a hardpacked base. To the side sits a big, rather innocent looking rock that we assumed inflicted the damage to his arm.