The National Park Service is ending efforts to recover the wreckage of a flightseeing plane near Denali and the bodies of five people inside, saying harrowing conditions at the crash site create too much risk for rescuers.

A park service helicopter reached the crash site Friday morning and a ranger spent an hour searching the aircraft while suspended by a fixed rope. The K2 Aviation de Havilland Beaver is perched on a hanging glacier on the north side of a 10,500-foot ridge about 14 miles from the summit of Denali.

Officials have now determined the steepness of the terrain, avalanche hazard and the condition of the aircraft "exceed an acceptable level of risk" for a recovery operation, National Park Service spokeswoman Katherine Belcher wrote in a statement Friday.

Five people — a pilot from Michigan and four passengers from Poland — were aboard when the flightseeing plane crashed Saturday on a remote mountain deep in the Alaska Range. It was the deadliest accident in recent history for an air taxi flying into Denali National Park and Preserve.

Bad weather persisted for days after the crash, allowing just a 5-minute window for a mountaineering ranger who dropped to the wreckage by rope Monday to confirm that four people were dead and a fifth was unaccounted for.

On Friday, better weather allowed a high-altitude helicopter to get a ranger to the wreckage before 10 a.m., Belcher said. The search of the wreckage lasted an hour.

The body of the fifth victim was found inside, Belcher said.

"Hazards at the crash site include, but are not limited to, avalanche danger, steep snow/ice, crevasses, unstable seracs (blocks of ice loosely attached to the mountain) and aircraft-related concerns such as protruding pieces of jagged metal," she wrote. "The crevasse where the wreckage sits is a dangerous and potentially fatal terrain trap should even a small avalanche occur.

"The aircraft is broken in half behind the wing, and the tail section of the fuselage is actively pulling down the aircraft towards a glacier 3,500 feet below. Additionally, more than two and a half feet of new snow has fallen at the crash site and loaded the nearly 45-degree slope just above the aircraft.

"Recovering the bodies and the aircraft under the current conditions would require an extremely complex and unfeasible recovery operation. NPS looks at three primary factors when evaluating risk: severity, probability and exposure.

"Due to the unique challenges posed by the steepness of terrain, the crevasse, avalanche hazard and the condition of the aircraft, NPS has determined that recovery of the deceased and/or removal of the aircraft exceed an acceptable level of risk in all three factors and will not be attempted."

Clint Johnson, chief of the Alaska region National Transportation Safety Board, the federal agency that investigates plane crashes, said he agreed with the decision.

"It's a tough decision, but I support the (National Park Service's) decision 110 percent," Johnson said.

"We're used to working in tough spots, but this is out of our league," he said.

The decision not to recover the plane was unusual, he said. It's happened only a handful of times during his 20 years at the federal agency, he said.

The NTSB attempted a site fly-over Thursday, but cloud cover prevented the crew from flying directly over the crash site, Johnson said.

Weather permitting, the agency may attempt another fly-over in coming weeks, Johnson said.

To complete its investigation, the NTSB will be using photos taken by National Park Service rangers, and interviews with pilots who were in the area that day and with K2 Aviation. Johnson said his agency also has GPS tracking data from the plane.

"There's still a lot of information to gather," Johnson said. A preliminary report will likely be released next week, he said.

Of the 126 total fatalities on Denali — both aviation and mountaineering accidents — 44 of those bodies are unrecovered, according to Belcher.

The most recent unrecovered plane crash occurred in June 1997, when a Cessna 182 disappeared with four people onboard. The wreckage was never found, Belcher said.