The same is true of wood, fiber, and other organic materials.

The archaeological record of the region’s earliest periods is, in non-cave contexts, largely limited to durable stone tools that survive the chemical environment of the forest floor.

In cave contexts, the story is different.

The alkaline chemistry of limestone caves — calcium carbonate neutralizes much of the acidity that attacks bone in acid forest soils — and the protection from direct biological weathering create conditions where organic material can survive for thousands of years.

The caves of Prince of Wales Island and the broader karst region of southeastern Alaska therefore represent windows into the region’s past that are uniquely informative compared to the broader landscape.