Wreckage from a plane that went missing over Katmai National Park and Preserve in August was spotted Tuesday on the park's northern coast. Park Service officials said there was no indication that its four occupants survived the crash.

Katmai Superintendent Ralph Moore said he was notified by a local helicopter pilot, Sam Egli, that he had spotted portions of the aircraft, including a piece of the tail with identifying numbers, on a narrow section of beach about 10 miles northwest of Sukoi Bay. Mr. Egli was en route to an unrelated commercial flying job when he made the discovery.

The single engine floatplane, a deHavilland Beaver operated by Branch River Air Service in King Salmon, has been missing with its pilot and three Park Service maintenance employees since August 21.

The Park Service employees -- Mason McLeod, 26, and brothers Neal, 28, and Seth, 20, Spradlin -- had been working to tear down a deteriorating patrol cabin at Swikshak on the park's eastern coastline and were headed back to King Salmon when the plane piloted by Marco Alletto, 47, vanished. Another plane that departed the area 15 minutes later never received a transmission from Mr. Alletto. Weather conditions were so poor, that the second plane flew only about 500 feet above ground on the way back to King Salmon.

Sukoi Bay is north of Swikshak.

National Park Service and military personnel were headed to the site Wednesday morning to secure the debris and continue the search for additional wreckage. The accident investigation will be conducted by the National Transportation Safety Board.

The discovery of the plane comes after more than a month of aerial and ground searching by national park, military and civilian personnel. More than 60,000 miles of flying was done, at times with more than a dozen aircraft working search patterns over the 4 million acre park.

The area where the debris was found had been flown over by the National Park Service as recently as Monday, and rangers had walked the beach just a few miles west of the debris site. High tides and high east winds on Monday and Tuesday are thought to have helped make the debris visible from the air, the Park Service said.