The reverse design depicts an aerial view of mounds in the Marching Bear Group. Inscriptions are EFFIGY MOUNDS, IOWA, 2017, and E PLURIBUS UNUM.
Design candidates were developed in consultation with representatives of Effigy Mounds National Monument which was established in 1949. The park protects one of the largest remaining concentrations of ancient American Indian earthworks in the United States. It is considered a sacred landscape by members of many modern-day tribes whose ancestors once lived here. The majority of the mounds were constructed between one thousand and two thousand years ago. Often to inter the dead, but sometimes for ceremonial purposes, or to tell important stories. The park is home to more than 200 mounds in a wide variety of forms, including more than 30 animal or bird-shaped effigy mounds for which the park is named. Often more than 100 feet long individually, many of these animal and bird shaped mounds are perched high atop rugged bluffs overlooking the adjacent Mississippi River. Aside from preserving these tangible links to an ancient and highly creative people, the park features outstanding views of the Mississippi River Valley, and hosts many of the native plant and animal communities that sustained people in this area for millennia.