Matthew Greene, a 39-year-old high school math teacher from Pennsylvania, disappeared from the Eastern Sierra Nevada while hiking on July 16, 2013. He spent the summer of 2013 climbing with friends in the Mammoth Lakes area and was described as an experienced outdoorsman. Greene’s car had mechanical trouble, so he stayed behind and continued hiking solo. His last contact was a call to his parents on July 16 when he mentioned plans for another day on the trail. His phone last pinged near the Ansel Adams Wilderness and he was camping at Shady Rest Campground.

When Greene failed to return to his campsite or pick up his car, a missing person report was filed on July 29. Searchers recovered some belongings, including a guidebook with missing pages that outlined a route to Mount Ritter, prompting investigators to think he may have been attempting that climb. Despite extensive searches in difficult terrain, no trace of Greene has been found and he was later declared legally dead. Anyone who saw Greene in the Mammoth Lakes area around July 16 or who has information about his route is asked to come forward.