Because the Olympic Mountains are built from uplifted marine sediments, fossil-bearing limestone and sandstone occur at high elevations along the range. Hikers can encounter the remains of ancient sea creatures thousands of feet above sea level, direct evidence that the rock now forming the peaks once lay on the ocean floor.
Here's a strange reward for climbing this high. Because these peaks are made of old ocean bottom, the higher you go, the more sea you find. Hikers on the upper ridges walk right past shelly limestone and sandstone packed with the shapes of marine creatures, clams and shellfish that lived on a seafloor now thousands of feet above the waves. Fossils of sea life, near the top of a mountain. It's the whole story of this range in a single rock. The ocean didn't drain away from here. It got lifted up into the clouds.
Photo: Dllu · CC BY-SA 4.0
