Book Cliffs

The Book Cliffs are a series of desert mountains and cliffs in western Colorado and eastern Utah, in the western United States. They are so named because the cliffs of Cretaceous sandstone that cap many of the south-facing buttes appear similar to a shelf of books.

Stretching nearly 200 miles from east to west, the Book Cliffs begin where the Colorado River descends south through De Beque Canyon into the Grand Valley (near Palisade, Colorado) to Price Canyon (near Helper, Utah). The Book Cliffs appear mostly along the southern and western edge of the Tavaputs Plateau. The cliffs are largely composed of sedimentary materials. The Book Cliffs are within the Colorado Plateau geologic province.

In the Colorado stretch of the Book Cliffs, abandoned coal mines are present, as significant coal resources were present in the region. These mines are now generally capped for safety, but several fatalities of recreational hikers have occurred at these mines since 1989 (due to lack of oxygen/CO₂ gas inhalation).

In some places, "wild" horses can be found in the Book Cliffs, for example (in 2008), a band of four was spotted near the abandoned Gearhart coal mine in Mesa County, Colorado.

The Book Cliffs are one of the world's best places to study sequence stratigraphy. In the 1980s, Exxon scientists used the Cretaceous strata of the Book Cliffs to develop the science of sequence stratigraphy. The Book Cliffs have preserved excellent strata of the foreland basin of the ancient Western Interior Seaway that stretched north from the Gulf of Mexico to the Yukon in the Cretaceous time. Components of deltaic and shallow marine reservoirs are very well preserved in the Book Cliffs.

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