Mascall Formation of the John Day Fossil Beds


While staying at the Wilson Ranches B&B near Fossil, OR we spent a few days visiting the very interesting and wide-spread units of the John Day Fossil Beds National Monument.

On a somewhat stormy day, thankfully turning to mostly sun breaks, we journeyed to the Sheep Rock Unit. The Unit is subdivided into the Mascall Formation Overlook, Picture Gorge, the James Cant Historical Ranch, the Thomas Condon Paleontology Center, Blue Basin, Cathedral Rock and the Foree District.

The first stop was Dayville to fill up with gasoline, one of the few places in the entire John Day area to sell premium gas. Then it was off to visit the Mascall Formation Overlook.

The 15 million-year-old Mascall Tuff was formed by successive falls of ash from the Cascades’ volcanoes to the west and from the much closer Strawberry volcanoes to the east. The Tuff, consolidated volcanic ash, tends to be mostly brownish in color. It was somewhat dramatic in places, but had none of the beauty of the reds and blues in other parts of the National Monument.

Dayville Gas Station

Dayville Gas Station

Blue Basin formations

Blue Basin formations

Sheeprock behind Picture Gorge

Sheeprock behind Picture Gorge

Canyon walls of the John Day River were still covered in green

Canyon walls of the John Day River covered in green grasses (soon to turn brown)

Mascall Formation

Mascall Formation

Categories: Central Oregon OutingsTags: , ,

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