Figure 13.

This valley is cut into the Wellfleet outwash plain and completely crosses the lower Cape from Cape Cod Bay to the Atlantic. It is the largest valley on Cape Cod and the drift surface below the saltwater and freshwater peat is well below sea level. The Pamet River Valley is thought to have formed when a headward eroding spring sapping valley intersected the glacial lake to the east of lower Cape Cod and caused the lake to drain catastrophically.