Searchers Monday found the wreckage of a small plane in Denali National Park, with no survivors/NPS

A plane carrying four visitors from Poland and the pilot was spotted on the flanks of Thunder Mountain in Denali National Park, with all occupants either confirmed or presumed dead, the National Park Service said.

The plane crashed not far below the top of the mountain about 6 p.m. local time Saturday. Initial attempts to reach the site were hampered by poor weather. On Monday, however, Park Service mountaineering rangers took advantage of a brief window of clearing weather and were able to view the wreckage, a park release said. The plane was spotted near the summit of Thunder Mountain, a feature located roughly 14 miles southwest of the summit of Denali, in extremely technical terrain on a hanging glacier; the aircraft was in the area of a crevasse, according to the Park Service.

An NPS ranger was short-hauled to the crash site (suspended beneath a helicopter) where he dug through the snow that had filled the aircraft and found the bodies of four of the five passengers. There were no footprints or disturbances leading away from the site and there were no other signs to indicate any of the passengers made it out of the plane.

According to the Anchorage Daily News, the pilot made two calls by satellite phone in the hour after the crash and reported injuries.

The names of the pilot and passengers were being withheld pending notification of family members. A temporary flight restriction remained in place over part of Denali National Park and Preserve to minimize traffic in the area of the crash site. There was no immediate word on when, or if, the Park Service would try to remove the bodies and the wreckage. The plane, a de Havilland Beaver, was operated by K2 Aviation.

Thunder Mountain was described by the Park Service as more of a ridge than a mountain, stretching roughly a mile long from east to west and rising about 3,000 feet above both the Tokositna and Kahiltna Glaciers. Terrain in the vicinity of the crash site is characterized as extremely steep and a mix of near-vertical rock, ice and snow.