Photo courtesy of Patrick Mueller
The trail to Thunder Rock Cove in Samuel H. Boardman State Scenic Corridor is a short 0.8 miles with little elevation change, making it a great stroll along the Oregon coastal cliffs. From the trail there are great views to the north and south as well as down to Secret Beach, which is accessed via a spur from the trail to Thunder Rock Cove. But the main attraction is Thunder Rock Cove, a small cove sheltered by sheer cliffs complete with a natural arch and a very noisy sea cave.
When a large wave enters the cove, it wraps around into a sea cave set into the cliff. Large amounts of water and surrounding air are forced into the back of the cave, creating a lot of pressure. When the wave hits the back and when forces on the air and water cannot push any further, the wave and air are expelled backwards and create a thundering sound that reverberates through the rock on occasion. On a calm day this sound is still audible with the occasional wave, but it is much more pronounced during large swells and storms.