The slide deposit remained saturated because the surrounding soil and the incoming precipitation maintained a constant supply of water to the buried materials.

Without this continuous supply of water, the anaerobic conditions in the deposit would eventually have been disrupted as the deposit dried, and the organic preservation that made the site so significant would have been lost.

The water that maintained the preservation was, paradoxically, also the water that eventually began to expose the site.

The winter storm of 1969 to 1970 saturated the bank above the buried deposit beyond its stability threshold, causing the erosion that began to expose the wooden objects.

The same hydrological system that had maintained the preservation for 500 years was the system that finally began to breach it.