Why is there a rugged rocky coastline from Cape Perpetua to Heceta Head? To the north of Yachats there are long stretches of sandy beaches; to the south are the sandy beaches and dunes around Florence. This talk will answer the question by taking you back into deep time. You will learn about plate tectonics, Oregon's long geologic history, and a volcano in Yachats that erupted and deposited hard, resistant basalt rock some 37 million years ago. Yachats is built on the remnants of this volcano. We will learn how the volcano was eroded and reshaped to create the rocky coastline we see today, including the Devil’s Churn, Spouting Horn, and Thor’s Well.