The pilot's failure to maintain clearance with terrain while maneuvering in a remote mountainous region. Contributing to the accident was the pilot's improper decision to traverse the remote mountainous area in high-density altitude conditions with the airplane near its maximum gross weight. Contributing to the delay in the search and rescue (SAR) was the lack of a 406-MHz ELT signal, which would have allowed SAR responders to initiate a more timely search and find the accident site more quickly.