The OES visited Jeffers Mound on September 5, 2004. Jeffers Mound is all that remains of a much larger earthwork that once occupied the location that overlooks the Olentangy River. Researchers believe the mound was constructed by the Hopewell culture sometime between 100 BC and 400 AD. Evidence collected in the 1830s showed the original earthworks made a rectangular embankment about three feet high, two circular enclosures, a small mound in the center, and the 20-foot high Jeffers Mound. The area was surveyed in 1847 and published in the book Ancient Monuments of the Mississippi Valley. Some of the embankment walls and smaller mounds were still visible as late as 1930, but repeated plowing of the land for the 100 years prior had worn down all but Jeffers Mound. Ash, pottery fragments, layers of wood and two skeletons were discovered in the mound in 1866.

In the 1920s, Herman P. Jeffers purchased the land, including the mound. In 1954, a subdivision was platted for the land, but the mound was spared. In 1974, the mound was deeded to the Worthington Historical Society to ensure it would be preserved. Jeffers Mound was included in the National Register of Historical Places that year as well. In the late 1970s, archaeologists conducted excavations at Jeffers Mound finding the remains of a structure that once stood southeast of the mound. A 1985 dig found projectiles and other artifacts that suggested the Hopewell had used the area as a long-term settlement. Jeffers Mound is preserved today as a public park for anyone to visit and enjoy.