Frank Martinez was last seen on April 1, 2010 and was reported missing by relatives. U. S. Forest Service personnel found his truck parked at the top of San Dimas Canyon Road near the reservoir. In the vehicle were found his keys, which were in the ignition, and his cell phone. The windows were rolled down and there were no tracks leading away from the vehicle. Law enforcement officials and the San Dimas Mountain Rescue team of the Los Angeles County Sheriff's Department searched the San Dimas Canyon area as well as the shoreline of San Dimas Reservoir with dogs and a helicopter, but he was not located. The search was called off after two weeks.