On August 21, 2010, 20-year-old National Park Service employee Seth Spradlin vanished when a de Havilland Beaver floatplane carrying him, his brother Neal Spradlin, 28, fellow employee Mason McLeod, 26, and pilot Marco Alletto failed to reach its destination after departing Swikshak Bay for Brooks Camp. A second plane from the same location landed safely and reported deteriorating weather that forced low-altitude flight.

A multi-agency search covered thousands of air miles across the 4-million-acre park; no emergency locator signals were detected. On September 28, 2010, debris washed ashore on the park’s northern coast, and later more fragments, a tent and a duffel bag believed from the flight were recovered. Some items showed signs of exposure to high temperatures, but the main wreckage and the four men were never found and the NTSB could not determine a probable cause.

Anyone who was in or flew over Katmai National Park in late August 2010 or has information about that flight is asked to come forward.