(Portland, OR)  --  Search crews are looking for a missing, injured hiker near Mount Hood.  Clackamas County Search and Rescue says 30-year-old David Yaghmourian of Phoenix, Arizona, went missing Monday while hiking along the Timberline Trail.  Yaghmourian was reportedly hiking with a friend when he injured his knee and stopped to rest.  His friend went on ahead and says Yaghmourian failed to meet up with him at their designated meet-up area.