This event, described as a landslide, was more of a slumping rotation of a half mile wide area several hundred feet deep at the head of Box Canyon. Both sides of the valley may have deposited material, but the north side seems more a normal landslide of small proportions. The two sides have differing basalts, to the south very gray in color, while the north is dark red. There is presumably a fault connected to the canyon which is likely the cause of the slumping via earth movements or earthquakes weakening the area and triggering the event.

   Notice the very flat basin beyond the water in the photograph, this extends off-camera north, to the right, and south for miles in both directions, an area determined as lake caused sediments in origin, lacrustrine, on all the geologic maps available.

   There is other evidence which points to a fairly stable lake at a lower level as well. This would have been prior to the high level lake. There is a very flat portion of the basin for miles to the south up Smoky Canyon to the main basin containing today's High Rock Lake.