This following account is included in Willard’s Cumorah Land written by Willard Bean on pages 152-154. The quote most likely comes from the book Life of Samuel Kirkland, Missionary to the Indians. In time, I hope to verify the quote. In the mean-time, this is what Willard Bean reported as being taught by Samuel Kirkland.
The following link will get you to what is probably the original source document. Life of Samuel Kirkland, Missionary to the Indians. I have not yet found the page for reference, so for now this document is using the secondary source or Willard’s Cumorah Land.
Reverend Samuel Kirkland was one of the first Protestant preachers to venture into the Indian country. He visited some of the ruins in 1788. He writes as follows: “After leaving Kanawagas (an Indian village, now Avon), I traveled 26 miles and encamped for the night at a place called ‘Joaki’ on the river Tonawanda. With my Indian guide, I went six miles from camp where we found an open area which the Indians called Tegatainghque, which means a double fortified town or a town with a fort at each end. One fort contained about four acres and the other possibly twice that. There was a ditch four or five feet deep around the former fort. A small stream of water with a high bank circumscribes nearly one-third of the area. There were six avenues or openings in the fort and a dug-way leading from the works to the water. Near the northern fortification, which is situated on high ground, are the remains of a funeral pile. The earth is raised about six feet above the natural surface.
“From many concurring accounts which I have been able to get from elderly Indian historians from several tribes, there are well defined traditions that long before the white man came here there was a great war in these parts that lasted many moons. An old gray-headed Indian told me that he and his progenitors for generations back had lived among these ruins. He said that many ages ago, before his people knew anything about firearms, there was a great war in these parts. They then fought with bow and arrow, cutting swords, spear, javelin, war-clubs, death-mauls, slings, and other ways to kill. He also said they wore jackets or coverings for their bodies made of willows and split moon-wood and a thick pad on their heads and that the dead were so many that they could not be counted. He explained that all those killed inside the forts had to be buried because of the stink which accounted for the funeral pile we had seen in one of the forts. All their historians agree that it was many ages ago. An age means about 100 snows, or years.”