Natural Resources, School of


Date of this Version



From the UNL website, online at


Bob Diffendal wrote text and Les Howard created maps for new Lewis and Clark signs at Ponca State Park on the Missouri River.

The Corps of Discovery led by Meriwether Lewis and William Clark reached what is now southeastern Nebraska on July 10, 1804. It arrived at the point on the Missouri River adjacent to what is now Ponca State Park on August 22, 1804; and entered fully into South Dakota on September 8, 1804. Over this span of nearly two months members of the expedition saw and described many geologic features. The locations of some of the more prominent ones that were noted by William Clark are shown on the perspective view.

The Geology of Ponca State Park: Two wells drilled near Ponca State Park’s Missouri National Recreational River Resource and Education Center have revealed information about the rock formations in this area.