These pictures where taken in The Bisti Wilderness Area that was once covered by an ancient sea,
the Western Interior Seaway. As the water slowly receded, prehistoric animals survived
on the lush foliage that grew along the many riverbanks.
When the water disappeared it left behind a 1,400-foot-thick (427 m) layer of jumbled sandstone,
mudstone, shale, and coal that lay undisturbed for 50 million years.
6,000 years ago the last ice age receded, exposing fossils, petrified wood, and eroding
the rock into the hoodoos now visible.

The variety of shapes formed by erosion is unlimited.