Bad Lands of Dakota
In the Dakotah (Dakota) Territory, the area know as the Bad Lands, is a sunken area thirty miles wide and ninety miles long. It is a type of arid terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. From the bottom of this sunken plain rise domes, pinnacles, monuments, and massive walls. The most impressive feature of this scene is the multitude of fossil bones which appear built into the massive masonry of this mimic architecture.
Winchell, Alexander Sketches of Creation (New York, NY: Harper & Brothers, 1870)