The 26-mile stretch of shore extending from Florence to Yachats is one of the most rugged and scenic parts of the Oregon Coast. Along most of this part of the coast the shore is bounded by basalt bedrock of varied types. Through differential erosion of the basalt, the many landforms, such as headlands, rocky shores, reefs, and sea stacks, that impart the rugged character to the coast have been and are still in the process of being developed. In places where the basalt bedrock is least resistant to erosion, small embayments with bay-head beaches have been formed, and areas where the bedrock is sedimentary are characterized by coastal plains as much as 4 miles wide. The larger areas of coastal plain are also areas of sand dunes; here the surface configuration is attributed to dune development that has gone on from late Pleistocene to the present.