Details of Disappearance
Xu was last seen in Blue River, Oregon on November 4, 2007. He went to the Three Sisters Wilderness area for a day hike, summiting Olallie Mountain. A couple who were also hiking encountered him at the mountain peak at about 1:30 p.m.; they said he spent only a few minutes before turning around and descending, apparently in a hurry. He never returned home and has never been heard from again.
His white 2003 Chevrolet Impala with the Oregon license plate number XVH 416 was found parked on Bear Flats near Terwilliger Hot Springs at the Olallie trailhead on November 6. Inside it was Xu's cellular phone, his heavier jacket, and part of a hiking book, 100 Hikes in the Central Oregon Cascades. The other half, which included the trail map for the route Xu planned to take, was found in the woods in the French Pete Creek drainage area on November 15.
Authorities believe Xu got lost or injured in the wilderness. He and his wife were avid hikers and he was very physically fit for his age. His case remains unsolved.