We've discussed Dendo Island a few times in the last five years of the blog. As portrayed in the following excerpt, a battle between Indian tribes took place in this area in 1730. Due to the vernacular of the time, Hewitt's Hill must have been a well-known spot in Menasha, or Doty Island. However, that description unfortunately doesn't allow me to tell you exactly where that was. An old zoning map from 1931 shows an area called "Hewitt's Addition" from Garfield Avenue south between Randall Street and Railroad Street, so it may have been in this area.
"The Battle of the Raven, 1730, was fought near Washington street. The Fox Fort stood on Hewitt's Hill. The Winnebago Fort was on Dendo Island. The separating stream is now Garfield Street. The battle between these two nations lasted six weeks, until the French Capt. Sier Marin arrived and took sides with the Winnebagos. One morning a raven was seen to enter the Fox Fort, by which sign Marin knew the Foxes had fled in the night."
from: Historic Sites in the City of Menasha and Near by Region, Publius V. Lawson, LL. B. in the 1920-21 Menasha City Directory
A better quality map (and scalable, too) is available at this link: http://content.wisconsinhistory.org/cdm/ref/collection/maps/id/13663/
As described at the Wisconsin Historical Society website, "This map is pen and ink on paper and shows part of the city of Menasha, local streets, Dendo Island, part of Lake Winnebago, and part of Little Lake Butte Des Morts. Little Lake Butte Des Morts and Dendo Island are outlined in blue ink. Also included are annotations in red ink and "Summer 1881" is written in black ink."