Monday, 2 February 2009


by Heidi Henderson

Chuckanut Drive, in northwestern Washington provides a visual feast from sea to sky.

An amazing array of plants and animals call this coastline home. For the fossil enthusiast, it is a chance to slip back in time and have a bird’s eye view to a more tropical time with a visit to the Chuckanut Formation. Snug up against the Pacific Ocean, this 6000m thick exposure yields a vast number of tropical and flowering plants that you might see in Mexico today. Easily accessible by car, this rich natural playground makes for an enjoyable daytrip just one hour south of the US Border.

Shaping our World



Washington is Born


This dynamic movement has created the landscape we see today and helped form the fossil record that tells much of Washington’s relatively recent history – the past 50 million years.

Chuckanut Formation

The area we will be visiting along Chuckanut Drive is much younger than other parts of Washington. The fossils we will visit lived and died some 40-55 million years ago, very close to where they are now, but in a much warmer, swampy setting.




Inset: Mammal Fossils in Washington

While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation.

Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and river ways of the Pacific Northwest 50 million years ago. The movement of these celebrity vertebrates was captured in the soft mud on the banks of a river, one of the only depositional environments favorable for track preservation.

Sidebar: Fossils Must be Dinosaurs…

We can thank Mr. Spielberg and popular culture for the fact that most people think of dinosaurs when they think of fossils. The bone record is actually far less abundant that the plant record. While calcium rich bones and teeth fossilize well, they often do not get laid down in a situation that makes this possible.

Look around at the site today and the abundance of plants and lack of visible animal life. They are far fewer animals than plants and consequently in a setting such as this far fewer animals in the fossil record. It is the reverse at some sites, i.e. the Gobi desert and Alberta, but in the Chuckanut, this is the way it plays out.

In Alberta, most of what we find are small bone fragments from vertebrates. This colors our notions of what the world must have looked like. It shows us only one small piece of the puzzle as to what life must have been like in an area when part of the fossil record is missing.

1 comment:

Anonymous said...

1. I wonder if the coal deposits in Bellingham are part of the Chuckanut Formation.
2. I wonder if there's a possibility that we may find a diatryma footprint, or traces of some other large animals. A big floodplain would seem to be a feasible habitat for bigger animals.
3. I note some strata of the Chuckanut Formation contain rounded quartz-granite type pebbles. Did these wash here from the Rocky Mountains before the Cascades existed?
Thanks for your interesting article.