Near Wall in Pennington County, South Dakota — The American Midwest (Upper Plains)
Jungle on a Seabed
The sea's signature is ammonites, baculites, and clams, pearly fossils entombed in a fossil mud called the Pierre Shale. This shale is exposed in the gully below you.
A jungle sprang up after the sea drained away about 65 million years ago. For a long time tree roots broke up the shale, and chemicals from decaying plants produced a yellow soil. About 37 million years ago sediment from the west washed over the jungle.
The jungle rebounded, converting the new sediment into a red soil. Buried by later sediments, both yellow and red soils were fossilized. We call them the Yellow Mounds Paleosol and the Interior Paleosol.
Location. 43° 50.606′ N, 102° 11.683′ W. Marker is near Wall, South Dakota, in Pennington County. Marker is on Badlands Loop Road (State Highway 240) 0.3 miles east of Conata Road (Road 509), on the right when traveling east. Touch for map. Marker is in Badlands National Park (fee to enter) at the Yellow Mounds Overlook near Dillon Pass. Marker is in this post office area: Wall SD 57790, United States of America.
Other nearby markers. At least 3 other markers are within Born of Volcanos (approx. 2.7 miles away); Journey to Wounded Knee (approx. 4.8 miles away); High Security (approx. 6.3 miles away).
Also see . . . Badlands National Park. "When the Lakota first encountered the striking, moon-like landscape, they aptly called the area “Mako Sica” or “bad land.” Early French trappers also described the area as “bad land” after difficult travels over the rugged terrain." (Submitted on December 27, 2007.)
Additional keywords. Badlands National Park
Categories. • Natural Features •
Credits. This page was last revised on June 16, 2016. This page originally submitted on December 27, 2007, by Keith L of Wisconsin Rapids, Wisconsin. This page has been viewed 1,564 times since then and 30 times this year. Photos: 1, 2, 3. submitted on December 27, 2007, by Keith L of Wisconsin Rapids, Wisconsin. 4. submitted on January 6, 2008, by Mike Stroud of Bluffton, South Carolina. • Craig Swain was the editor who published this page.