Spearfish Canyon

Approximately 600 million years ago in the Precambrian, the area was covered by a sea.

As waters subsided and land masses began to appear 60 to 30 million years ago (between the Paleocene and Oligocene epochs), drainages such as Spearfish Canyon formed as softer rock was eroded away.

As for bird species, turkeys, bluejays, woodpeckers, cliff swallows, chickadees, and golden or bald eagles are seen in the area.

It is often studied by geologists due to the extreme old age of the Precambrian rocks exposed by the creek bed.

The Cambrian to Ordovician Deadwood Shale at the bottom lies on an unconformity above Precambrian rock and can be identified by its brown color.