Iowa: Effigy Mounds National Monument

The monument was founded to preserve and protect a representative example of prehistoric American Indian moundbuilding culture and the wildlife and scenic wildness around the area. While moundbuilding was widespread throughout the eastern half of North America, only in the upper Mississippi Valley was a culture established that specialized in mounds built in the shape of living creatures such as eagles, falcons, bison, deer, turtles, lizards, and especially bears.

Site Office

Effigy Mounds National Monument

151 Highway 76

Harpers Ferry, IA 52146-7519

ph.: (319) 873-3491

Web site:

Effigy Mounds National Monument, established by presidential proclamation in 1949, preserves 191 examples of ceremonial and burial earthen mounds built by a variety of prehistoric Indians, as well as a large collection of related artifacts. The monument contains 1,481 acres that include forests, tall grass prairies, wetlands, and rivers. The site contains a number of linear and conical mounds. Still, the monument is best known for the twenty-nine mounds built in the shape of living creatures such as eagles, falcons, bison, deer, turtles, lizards, and especially bears, called Effigy Mounds. Moundbuilding culture was rich and varied, and this historic site provides a good introduction to the histories of the moundbuilding peoples.

Early European settlers and later nineteenth century archaeologists did not agree on the origin of the mounds and the people who built them. A variety of myths grew up in an attempt to explain the mounds, and some of these myths were used to help justify unjust policies toward Indians by the United States in the nineteenth and early twentieth centuries. Careful study of the mounds during the twentieth century has helped to clarify who built the mounds and why. Still, much about the culture of the people who built the mounds, and complete knowledge about how the mounds were used, remains debatable. Since its founding, the park has embarked on a mission of conserving the mounds and the surrounding landscape, making hiking trails and educational programs available year-round.

Moundbuilding Culture

The mounds at Effigy Mounds National Monument date back over one thousand years and are part of a larger moundbuilding culture that originated in the Upper Mississippi Valley and the eastern half of North America during what is known as the Woodland Period. This era lasted from 1000b.c.e. until 1200c.e. Mounds were built throughout the Woodland Period, but the type of mounds and their uses would change throughout that period. During the Early Woodland Period (1000b.c.e.-300 b.c.e.), conical mounds (round-shaped) were constructed and mostly used for burial purposes. During the Middle Woodland Period (300 b.c.e.-400 c.e.), more complicated mounds were built. Larger conical and linear (cigar-shaped) structures, as well as mounds that combined conical and linear shapes, were formed. Some of those continued to be used for burial, while others took on ceremonial uses. A few mounds excavated at Effigy Mounds National Monument are from that period.

It was during that time that a civilization known as the Hopewell occupied much of the Upper Mississippi Valley. Between 400 c.e. and 1200 c.e., or the Late Woodland Period, a new culture of moundbuilders constructed conical, linear, compound, and, for the first time, effigy-shaped mounds that resembled a wide variety of living creatures. It appears that very few effigy mounds were used for burials, and the few that were held the remains of what probably were some of the most important religious and civic leaders of the group. Archaeologists believe it more than likely that instead of being burial mounds, the effigy mounds had symbolic or ceremonial purposes. Those mounds may have been symbols of the moundbuilders’ clans, monuments or totems to animal spirits, or territorial markers.

Archaeologists speculate that the builders first cleared a large area and then made an outline of their proposed shape to help guide their work. They then began the process of forming the mound. Individuals or small groups of people used sticks and reed baskets to dig and then transport baskets of rich soil and yellow clay from the surrounding areas and riverbanks. It probably took hundreds of trips to form the mound into the right shape and height. Evidence of fires set on the mounds at the head, flank, or heart of the animal likeness has been found. These fires were probably used at some point for specific ceremonies. Conical mounds are typically two to ten feet high and twenty feet in diameter. Linear mounds range from two to four feet high and six to eight feet across. Some have been found to reach one hundred feet across. A typical effigy mound is three to four feet high, twenty feet wide, and seventy-five feet long. The Great Bear Effigy Mound at the monument is 137 feet long and 70 feet wide at the shoulder.

Excavations of the park over the years have led archaeologists to conclude that Indians of the Oneota culture probably supplanted the Effigy Mounds people between the fourteenth and fifteenth centuries. Other tribes living near the monument that may have lived in the area after the Effigy Mound people include the Ioway, for which the state of Iowa is named. During the seventeenth century, when European explorers and traders began to explore and look for animal skins and trade in the area that is now within the monument, Indian occupation of the area ended.

Early Archaeology of the Effigy Mounds

Louis Jolliet and Father Jacques Marquette were the first white men to reach the northeast region of Iowa while exploring the Wisconsin and Mississippi rivers in 1673. Nevertheless, it was other explorers, fur traders, and finally western settlers who recognized the mounds as things built by human hands. The first written account by a European of the effigy mounds in northeast Iowa was in fur trader Jonathan Carver’s Travels Through the Interior Parts of North-America in the Years 1766, 1767, and 1768 (1778). In the early accounts, some wondered if an ancient civilization had constructed the great earthworks. Much speculation about the creators of the mounds and their function took place, but it was not until the mid-nineteenth century that the first systematic research of the effigy mounds in northeastern Iowa took place. In 1881 Theodore H. Lewis and Alfred J. Hill surveyed the mound groups of the Mississippi River Valley. The Lewis-Hill surveys produced first-rate maps of a large number of mound groups, many of which were within the present-day monument. Still, the maps reveal that hundreds of mounds that were initially surveyed were gone by the time the monument was established in 1949.

After those initial surveys, several years passed without much scientific study of the mounds. At the end of the nineteenth century, Ellison Orr (1857-1951), who grew up in the region, became interested in the mounds. He spent much of his life documenting them with maps and surveys and collecting artifacts at the mounds. As a lay archaeologist, he gained a national reputation for his early work on the mounds. During the Great Depression, the Federal Emergency Relief Administration (FERA) sponsored an important archaeological survey of the mound sites in northeastern Iowa, and Orr was appointed the head surveyor. That survey led to a presidential proclamation in 1949 establishing the National Monument on one thousand acres. More acreage was added in 1951 and 1961 to help preserve additional mounds.

Myth of the Moundbuilders

Unable to recognize the earthen mounds as products of the ancestors of the native peoples living in the Upper Mississippi Valley–because it was believed that the contemporary native peoples lacked an advanced culture and were incapable of such construction–European explorers, westbound settlers, and early archaeologists developed a mythical explanation for the origins of the mounds. A whole mythology, and even a religion, developed that focused on a “lost civilization” of giants who had once lived in North America but had been destroyed by contemporary native peoples. Others argued that native peoples from Mexico and Central America like the Toltecs had built the mound structures. In short, the legends contended that the mounds had to have been created by some group–almost any group would do–other than the American Indians currently occupying the lands where the mounds stood.

For about a century, the myth was advanced and often used by a variety of nonnative peoples to justify removal of, and unfair policies toward, those American Indians who occupied lands coveted by non-Indian people. Those non-Indians justified violent removal by arguing that the same native peoples under attack had been in earlier generations the destroyers of the advanced civilization that was believed to have constructed the mounds. Finally, in the 1880’s, many in the scientific community began to debunk those myths. The best known of these scientists was Major J. W. Powell, founder of the Smithsonian Institution’s Bureau of American Ethnology. Cyrus Thomas, in a seven hundred-page volume, showed overwhelming evidence that the mounds were indeed the creations of known American Indian nations or their ancestors, not some “lost civilization.”

Places to Visit

A visit to the monument will probably begin with a stop at the visitors’ center. A museum within the center provides an overview of the prehistory and history of the region. It also contains artifacts found during the years when the mounds at the monument were being excavated. Examples of the maps and surveys conducted over the years also can be seen in the museum. A section of the museum concerns the ongoing efforts for mound conservation. A significant part of the monument’s mission remains conservation of the earthwork structures. Since the nineteenth century, when many of the original surveys of mounds were conducted, more than 80 percent of the known mounds have been destroyed through logging, agriculture, and other types of development. A fifteen-minute video outlining the history and culture of the moundbuilding civilization provides a good background for further exploration of the monument. The visitors’ center is open year-round from 8:00 a.m. to 4:30 p.m. except for New Year’s Day, Martin Luther King, Jr., Day, Presidents’ Day, Veterans Day, Thanksgiving, and Christmas Day.

Besides the mounds, the 1,481 acres of the monument contain many of the plants and animals that are typical of the Upper Mississippi region. The best way to see the monument is by taking either a ranger-guided tour (available May to September) or a self-guided walk of the many trails. The Yellow River divides the monument into two units, North and South. A 3.5-mile hike in the North Unit to Hanging Rock (named for a rock formation that at one time jutted out over the edge of a bluff and was blasted to make way for the railroad) takes you by several effigy mounds including the Little Bear Mound and the Great Bear Mound. Also of interest in the North Unit is Fire Point, believed to be a favorite spot of the Woodlands people for fires, possibly for ceremonial purposes. To explore the South Unit, a four-mile hike leads through hardwood forest and restored tall grass prairie to the Marching Bear Group Effigy. This series of mounds is composed of ten bear and three bird effigy mounds. It is one of the largest effigy mounds remaining in the region. Picnicking and camping are not allowed in the monument, but picnic and camp sites are available nearby on Highway 76. Motels and restaurants can be found in the nearby towns.

Effigy Mounds National Monument is just one of the places to see when visiting the area. Eight miles south of the monument, visitors can find Pikes Peak State Park. Just eight miles north of the park are Yellow River State Forest and Wyalusing State Park. Prehistoric Indian mounds are also preserved at those parks, as well as at other places throughout southern Wisconsin and northeastern Iowa. Across the river at Prairie du Chien, Wisconsin, is the Villa Louis State Historic Site. Prairie du Chien was an important point of exploration and settlement for early European settlers in the Upper Mississippi Valley.

For Further Information

  • Alex, Lynne Marie. Exploring Iowa’s Past: A Guide to Prehistoric Archaeology. Iowa City: University of Iowa Press, 1980. Examines various sites and artifiacts from the archaeological record.
  • Clark, Mallam R. Iowa Effigy Mounds Manifesation: An Interpretive Model. Iowa City: Office of the State Archaeologist, University of Iowa Press, n.d. More technical information on the construction of the Effigy Mounds.
  • Effigy Mounds National Monument and the Office of the State Archaeolgist. Prehistoric Cultures of Iowa: A Brief Study. Iowa City: University of Iowa Press, 1995. A booklet containing reprints which outline the development of prehistoric cultures of Iowa.
  • Mainfort, Robert C., and Lynne P. Syllivan, eds. Ancient Earthern Enclosures of the Eastern Woodlands. Gainesville: University Press of Florida, 1998. Edited volume that explores topically several ancient sites in North America.
  • O’Bright, Jill York. The Perpetual March: An Administrative History of the Effigy Mounds National Monument. Omaha, Nebr.: National Park Service, Midwest Regional Office, 1989. Examines the history of the historic site and the way the site has changed.
  • Silverburg, Robert. The Mound Builders. Athens: Ohio University Press, 1986. This work is an abridged edition of Mound Builders of Ancient America: The Archaeology of a Myth (Greenwich, Conn.: New York Graphic Society, 1968). It explores the creation and debunking of the legends that evolved concerning the construction of the mounds.