Avalanche debris was spotted during a search for a missing Marine who failed to return from a backcountry skiing trip through the Sierra Nevada, California authorities said Sunday.
First Lt. Matthew Kraft began trekking the rugged Sierra High Route on Feb. 23 and was scheduled to complete it Monday or Tuesday near Bridgeport, northeast of Yosemite National Park.
The search on Sunday will primarily be air-based because "ground searching has proven to be too dangerous due to snow instability and avalanche concerns," the Inyo County Sheriff's office said in a statement. Much of the area was deemed impassable because of heavy snow and rock falls, the statement said.
Searchers on Friday located a Jeep that Kraft parked at the start of his trip near Independence, about 130 miles south of Bridgeport, Inyo County Sheriff's spokeswoman Carma Roper said Saturday.
Crews from local, state and federal agencies were searching a 400-square-mile area from Yosemite down to Sierra and Inyo National Forests and Kings Canyon National Park, Roper said.
A series of winter storms has dumped record amounts of snow in the Sierra and led to avalanche warnings in the backcountry.
Kraft is an infantry officer who received survival training in the field, military officials said.