Frederic W. Putnam of Harvard University's Peabody Museum did much to advance knowledge of Serpent Mound. On his first visit, he wrote of being overwhelmed with awe and admiration and feeling a demand for an interpretation of the mystery so that the unknown might become known. Between 1887 and 1889, he studied the site, excavating parts of Serpent Mound, three nearby burial mounds, and a village site. He also helped preserve Serpent Mound by inspiring his colleague at the Peabody Museum, Alice Fletcher, to raise money to purchase the site for future generations. Putnam's cross-section of the oval embankment at the Serpent's head showed a feature that may be the open mouth or eye of the Serpent, or an object in the Serpent's mouth.