A massive search is underway for a 60-year-old man who went on a Memorial Day hike in California's Lake Tahoe area and has not been heard from since, authorities said.
The hiker, Jason Coughran, went missing in the Desolation Wilderness area, southwest of Lake Tahoe, according to the El Dorado County Sheriff's Office.
Coughran was hiking into Desolation Wilderness from nearby Fallen Leaf Lake, according to authorities.
He was believed to have been near Angora Peak around 11 a.m. on May 25 and was last heard from later that day, at approximately 4 p.m. local time, the El Dorado County Sheriff's Office said.
The following day, the sheriff's office put out an alert about the overdue hiker while urging other hikers to contact them if they came across Coughran.
In the days since he was reported missing, nearly 200 personnel have joined the search and rescue effort, according to the sheriff's office. Over two dozen agencies and community partners, including the California Air National Guard, are involved in the search, authorities said.
The search and rescue effort has included volunteers on the ground and in vehicles, helicopter crews and K9 teams, authorities said.
Search and rescue personnel with high-altitude experience are also involved, according to the Placer County Sheriff's Office, which said the "highly trained teams are equipped to operate in complex and challenging terrain."
Coughran is described as 6'2" and 150 pounds, with brown hair, hazel eyes and an athletic build. His clothing is uncertain, though he may be wearing khaki shorts, authorities said.