The plane, a Cessna 182, was en route from Hoonah to Juneau when it disappeared Sunday morning.
Wreckage, including an engine and a propeller, was discovered at the base of a 50-foot cliff near the island's Eagle Crest Peak late Sunday afternoon.
But search teams looking for the plane's occupants and the crash site had to turn back due to bad weather and rough terrain.
Conditions remained rainy, foggy and overcast Monday when a team hiked up to search the area.
NTSB investigator Clint Johnson said wreckage was found at the 3,100-foot level on a mountain, about 500 feet from the summit.
Much of it was in pieces scattered around that area, he said.
The terrain leading to the crash site was "very steep, very treacherous," Johnson said.
Names of those killed had not been released Monday.
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