SAN FRANCISCO, Aug. 14 (Xinhua) -- A plane that crashed last month in Glacier Bay National Park, U.S. state of Alaska, was a few hundred feet below a high ridge when it struck the mountainside, killing three people aboard, according to an official preliminary report released on Wednesday.

The 1948 Beechcraft Bonanza left Juneau, the capital city of Alaska, on July 20 for Yakutat, but crashed into the east side of Mount Crillon, one of the higher mountains of the coastal Fairweather Range, the U.S. National Transportation Safety Board said in the report.

The plane's tracking signal stopped at an altitude of about 10,875 feet (about 3,315 meters), 345 feet (about 105 meters) below the top of the ridge, according to the report, which also referenced a forecast warning of clouds obscuring mountaintops in the region.

An aerial search on Aug. 5 revealed "portions of highly fragmented airplane wreckage" at about 6,200 feet (about 1,890 meters), more than 4,500 feet (about 1,372 meters) below the area where authorities believed the plane initially crashed, the report said.

The discovery of the plane came more than two weeks after the U.S. Coast Guard suspended an extensive search for the plane.

Any information in the report is preliminary, said Clint Johnson, the NTSB's Alaska chief. A more comprehensive report, including any probable cause of the crash, is expected to be released next year. ■