♪♪ Kohlsdorf: If the saying is true and a single picture truly is worth a thousand words, then scenic views along the Great River Road must contain volumes of stories about the history, geology, and culture of Northeast Iowa.

Just outside Harpers Ferry, Effigy Mounds National Monument displays some of the region's oldest human history.

Twenty different regional tribes are credited with building the Effigy Mounds, which date back at least 1,000 years before French and Canadian traders settled in the area.

Park trails guide visitors past 206 prehistoric mounds, or effigies, shaped to represent animals such as bears and birds.

Some served as burial grounds, while others may have been created for ceremonial purposes to mark sacred ground.

Managed by the National Park Service, Effigy Mounds National Monument encompasses Clayton, Dubuque, and Allamakee County.

The ceremonial markers can be found throughout the upper Mississippi River Valley, stretching through Wisconsin.

Minnesota, Iowa and Illinois.