An effigy mound is a raised pile of earth built in the shape of a stylized animal, symbol, religious figure, human, or other figure. The Effigy Moundbuilder culture is primarily associated with the years 550-1200 CE during the Late Woodland Period, although radiocarbon dating has placed the origin of certain mounds as far back as 320 BCE.

Effigy mounds were constructed in many Native American cultures. Scholars believe they were primarily for religious purposes, although some also fulfilled a burial mound function. The builders of the effigy mounds are usually referred to as the Mound Builders. Over 3200 animal-shaped effigy mounds have been identified by the Wisconsin Historical Society in the upper midwest.

Native North American effigy mounds have been compared to the large-scale geoglyphs such as the Nazca Lines of Peru.