Visiting John Day Fossil Beds

Hi Blog!

On our way to Bend this past weekend, we passed the John Day Fossil Beds National Monument. We made a promise to ourselves that we would return. On Tuesday, April 16, 2019, we began our journey from John Day toward Picture Gorge, the entrance to the National Monument.

Our first stop was the Mascall Formation Overlook. High above the John Day Valley, we were able to look down into the Picture Gorge.

The Mascall Formation is one of the newest formations (geologically speaking) in this area. When this ash fell, the area was a savanna-like landscape with broad flood-plains with scattered lakes. The grass and forest environment was home to swift, long-legged, hoofed animals like early grazing horses and camels. The Mascall environment also attracted true cats, along with four-tusked elephants. Who knew there were elephants in Oregon!

Our next stop was the Thomas Condon Paleontology Center and Visitor Center, named after the prominent 19th-century Oregon scientist who first recognized the significance of the fossil beds. Colorful murals, fossil displays, and a paleontology laboratory are some of the main features. After watching the park video, we toured the various fossil displays.

When we started our adventure, we had no idea how extensive the John Day Fossil Beds were. It truly is a "Journey Through Time." There are eight separate environments encased in the eight different ash falls. The oldest are the Clarno Nut Beds. The fossils in this strata were from a wet, lush, semitropical forest. The newest layer is the Rattlesnake Assemblage which consists of a grassland populated by pronghorn, beavers, ground squirrels, dogs and true cats. In this one location, there is a record of eight separate ecozones separated by millions of years!

After the Visitor Center, we drove over to the James Cant Ranch, which had served as the park headquarters. We took a short hike to take in the view of Sheep Rock.

After a picnic lunch, we drove over to Blue Basin. The gravel trail ascends to an amphitheater carved out of the blue-green claystones of the John Day Formation. The volcanic ash, now turned to stone, contains a rich variety of vertebrate fossils.

The trail follows a creek. There are a dozen metal bridges which take us up to the base of the blue-green cliffs.

The rich blue-green color of the claystone was caused by chemical weathering of a mineral called celadonite. This happened millions of years ago as water moved through the alkaline ash beds under high pressure.

As the rocks weather, the blue-green color is washed downstream.

We made our way back down from the Blue Basin and continued our journey along Highway 19. On our way to Cathedral Rock, we stopped to see if we could find the Goose Rock. The material in this rock formation was so voluminous that from here it flows all the way to the ocean! 

The goose head for which the rock formation is named is hard to see, but it is to the right of the topmost outcrop.

Our next stop was Cathedral Rock. The colorful greenish outcrop is capped with reddish ignimbrite (i.e. lava)!

Our last stop was the Foree Area. Here we could take in the sculpted green claystone capped by volcanic flows.

Erosion has left this island of claystone. There were signs of elk all along the trails in this area, but we never did spot one.

We truly enjoyed our "Journey Through Time" along the Oregon Scenic Byway through the John Day Fossil Beds National Monument.

We have one more day here in John Day and hope to get out on one last adventure. Stay tuned.