Today, Sequim averages around 16 inches of rainfall per year, in marked contrast to the 140 or more inches that fall on the western slopes.

During the late Pleistocene, the specific climate of the Sequim area would have been different from today’s, but the fundamental rain-shadow effect created by the Olympics was probably similar — meaning that the eastern Olympic Peninsula may have been somewhat drier than the rest of the peninsula even then.

This would have had implications for the vegetation communities of the area and, in turn, for the animal communities that depended on those plants.

Mastodons were browsers.