The Oregon coast between Yaquina Head and Government Point owes its scenic grandeur to a unique wedding of ancient and recent marine environments. Visitors to Beverly Beach State Park, located in the southern part of this coastal strip, have a rare opportunity to wander along a shoreline that some 15 m. y. (million years) ago, in Miocene time, was also a coastal area. Unlike the present coast, however, it was then the site of active volcanoes that erupted lava, fragmental debris, and ash both on the land surface and on the adjacent ocean floor. The Miocene geologic events are recorded in the rocks that are well exposed in present sea cliffs and surf-cut platforms near sea level and in roadcuts. The areal distribution of the major rock units (geologic formations) that crop out along this part of coastal Oregon is shown on plate 1. A diagram that shows the sequence and relative ages (stratigraphy) of rock units discussed in this guidebook article is shown in figure 3. This guidebook was written for visitors to this part of the Oregon coast in order to acquaint them with some of the intriguing geologic features that are well displayed and readily accessible. Those who desire a more detailed description of the geology of the region are referred to reports listed in the bibliography.