Mt hypothesis is that Fosset was flying his plane low down the small canyons and river beds. For some reason he flew into one of the steep walls of one of them. The impact caused the near vertical face to collapse on top of the wreckage concealing it from the searchers.

Terrain collapsing over a wreck is in without precedent. It happened to a plane that flew into a mountain in the Andes where part of a glacier covered it. It has, until recently, when parts started to come out of the bottom of the glacier, been a mystery what happen to the plane.

The Fosset crash site, deep in a steep walled canyon and covered by a rockfall, is well concealed. At some later date rains came and the canyon experienced a flash flood and washed the fleece and wallet out of the wreckage and downstream. The flood waters, channeled withing the canyon initially, spread out as it hit flatter terrain leaving the wallet and fleece in an are without any obvious stream bed. So, to the hiker, they appeared on flat terrain without any clue of how they got there.