The OES visited Serpent Mound on July 10, 2006. Located on a plateau outside the town of Peebles, Serpent Mound is the largest effigy mound in North America and one of only two effigy mounds in Ohio (the other being Alligator Mound in Licking County). For over 100 years, researchers attributed the Serpent Mound to the Adena culture, as many of the smaller mounds of the area were built by the Adena. But carbon dating in 1996 revealed the spectacular mound was most likely built by (or at least renovated by) the Fort Ancient culture around 1070 AD. The mound itself is 1,330 feet long with an average height of three feet. While several nearby mounds contain burials, there are no human remains in Serpent Mound. The mound also has some astronomical significance as the head of the serpent is aligned to the summer solstice sunset and the coils may point to the winter solstice and the equinox sunrise.
Serpent Mound was first mapped by modern culture as early as 1815. The site was surveyed for the Smithsonian Institution in 1846 and was published in the book Ancient Monuments of the Mississippi Valley. The book gave a detailed description and a map of the site. In 1886, Frederic Putnam raised funds to purchase the 60 acre site to preserve the mound. In 1900, the land and its ownership were granted to the predecessor of the Ohio Historical Society. In 1908, the Columbus Wire & Iron Works Company won a contract to built a 25-foot tall observation tower on the site. The tower was erected in September 1908 near the serpent's tail for the grand total of $500. The Ohio Historical Society opened a museum near the mound in 1967 and constructed a walkway around the mound. To check the hours of operation and cost of admission to Serpent Mound, visit the Ohio Historical Society's page by clicking here.