Key keywords: Grand Canyon National Park, missing person investigation, park rangers, public assistance request, person of interest, backcountry hiking safety, National Park Service, missing hiker James Liu, Bright Angel Trail, Phantom Ranch Grand Canyon National Park officials issued an urgent public appeal on Wednesday, asking visitors and social media users to help identify an unknown person linked to the ongoing investigation into the disappearance of 42-year-old hiker James Liu, a California resident who was first reported missing on May 14, 2024. Liu, an experienced backcountry hiker, had booked a 3-day solo permit for the Bright Angel Trail, with a planned stop at Phantom Ranch on May 12. Park records show he checked in at the South Kaibab trailhead on the morning of May 11, and shared a photo of his route with his partner that afternoon, confirming he was on track for his scheduled overnight stay at the ranch. Surveillance footage recovered from Phantom Ranch’s visitor center, reviewed by investigators earlier this week, shows Liu speaking with an unidentified individual at approximately 3:17 PM on May 12, roughly 20 minutes before Liu’s phone sent its final location ping from a remote area 2 miles north of the ranch, off the marked trail system. The unidentified person is described as a white male between 25 and 35 years old, approximately 6 feet tall with a slender build, wearing a neon blue rain shell, khaki hiking pants, a gray baseball cap with an unrecognizable outdoor brand logo, and carrying a large black overnight backpack with a trekking pole strapped to the side. Park rangers emphasized that the individual is not considered a suspect at this stage of the investigation, but is believed to be the last person to have interacted with Liu before he vanished, making his testimony critical to piecing together what happened in the hours before Liu’s disappearance. Initial search efforts, which launched within 6 hours of Liu being reported missing, included 12 ground search and rescue teams, 3 K-9 units, and 2 aerial surveillance helicopters, covering more than 120 square miles of rugged, remote backcountry terrain over the course of 10 days. The search was scaled back on May 25 after teams found no trace of Liu or his belongings, leading investigators to shift focus to witness testimony and public tips. Grand Canyon Chief Ranger Sarah Morales noted in a press briefing that peak tourist season brings more than 30,000 visitors to the park per day in May, meaning hundreds of people may have been in the Phantom Ranch area on the day Liu was last seen. “We know there are people out there who saw this individual, or who may have even spoken to him, and we’re asking them to come forward no matter how insignificant they think their observation might be,” Morales said. “Even a small detail about where he was going, or what he said about his plans, could help us bring answers to James’ family, who have been waiting for updates for weeks.” Anyone with information about the unidentified person, or details about Liu’s whereabouts, is asked to contact the Grand Canyon National Park tip line at 928-638-7805, or submit an anonymous tip through the National Park Service’s online portal. Park officials also used the appeal to remind visitors to always share their detailed hiking plans with someone outside the park, carry enough water and emergency supplies for unexpected delays, and avoid leaving marked trails without proper navigation equipment.