John Day Fossil Beds National Monument

John Day Fossil Beds National Monument, established in 1975, covers 14,000 acres divided into 3 seperate sections or units. We only had time to visit one of the units, the Sheep Rock Unit.

I really didn't expect to see much in this nearly treeless high desert of Eastern Oregon, so I was surprised. The drive through these steep, narrow canyone was actually quite impressive!

The fossils found here at John Day are from a period of the Cenozoic Age between 45 and 5 million years ago.

In the picuture below you may be able to see the red, green, and pink layered color variations of the John Day formation.

The John Day fossils are so plentiful and varied that scientists have been able to identify 8 different ancient ecosystems. The visitor center here has information and displays on each of the ecosystems or assemblages. They are as follows . . .

Rattlesnake Assemblage -
7 million years ago

This was a time of great upheaval in Oregon. Animals similar to todays horses, bears, deer, dogs, pigs, and cats suddenly found their lives changed by a violent volcanic eruption. Superheated ash and gases covered a 13,000 square mile of the once cool, semi-arid climate of Oregon that was their home.

Mascall Assemblage -
15 million years ago

This Oregon, with its mild climate and good rainfall, was savanna-like. The retreating hardwood forests were gradually replaced with lush grasslands.

Birch Leaf

Peccary Skull

Haystack Valley Assemblage -
20 million years ago

A time of grazers such as camels, rhinos, horses, and the calicotheres - a large clawed animal related to horses. A common predator during this time was the bear-dog (extinct today).

Bear-dog Skull

Kimberly Assemblage -
24 million years ago

This time period shows and Oregon with large forests with soft, ashy soils. The first true dogs appear in the fossil records during this time.

Small Tortoise

Turtle Cove Assemblage -
29 million years ago

The climate during this time in Oregon's history was cool and dry. There was abundent volcanic activity.

Dirked-toothed "Cat"

Bridge Creek Flora -
about 33 million years ago

Oregon's climate during this time was slightly cooler and drier. The tree that became Oregon's state fossil, the Dawn Redwood, was widespread.

The Dawn Redwood is a cousin, although much smaller, of the Giant Sequoia and Coastal Redwood trees that are found in California today.

This tree was believed to be extinct until a grove of them was found in China in 1943.

Hancock Mammal Quarry - about 40 million years ago.

During this time Oregon's climate was warm and humid. There was some volcanic activity.

Rhino Tusk

Clarno Nut Beds -
about 44 million years ago

In this time Oregon had a semi-tropical climate, hot and wet with lush forests.

Sycamore Leaf

Oak/Beech Family

Fern Frond

Hydrangea Flower

Catfish Skeleton

Another cool thing about the visitor center is that they have a lab where you can see the equipment that is used to prepare and study the fossils that are found here. There wasn't anyone working in it when we were here, but it was neat to see all the stuff!

There is also a display that tells all about what goes in to preserving a fossil - how it is stabilized with a special glue to keep it from crumbling, how the excess stony material is removed without damaging the fossil, and how molds are created so scientests can study them without actually handling or having access to the origional fossil.

Click on this picture to make it bigger and then check out the size of the skull sitting on the top shelf!

A fossil mold

Mom tried to trick me and told me there were big dinosaurs here that
would try and eat me, but she didn't fool me . . . I ain't scared of no fossils.
This big guy didn't hurt me a bit!