The landscape of the Chicago region has a limited range of elevation. One of the natural mounds and an early landmark disappeared at the hand of a local company for local building:
Long ago, a mound jutted up from the flood plain flatlands surrounding the Des Plaines River in what is now a mostly industrial area on the southwest side of Joliet.
It was a significant feature and guidepost for travelers plying the Illinois waterway in the earliest days of recorded history, and a mainstay on maps for decades. Some speculated it was a creation of the mound building civilization that had populated these lands for centuries, best known for its world class city at Cahokia.
Subsequent digging didn’t turn up valuable artifacts, but instead revealed valuable gravel and sand deposited during the ice age, and a short-lived company made quick work of Mount Joliet, dispersing its innards for use in roadways and other projects as the modern development of the region began in earnest in the second half of the 1800s…
Another feature used by centuries of travelers in the area has survived to the present day. In fact, besides giving river navigators a guide point, Mount Joliet may have been one of the landmarks as well along the Great Sauk Trail, an ancient roadway connecting the Mississippi River to what is now the Detroit area.
According to another source:
The mound was destroyed when it’s clay contents were mined to make sewer tiles by the Drain Tile Manufactory of the Joliet Mound Company in the 19th century.
White European settlers to northeast Illinois altered the landscape when they moved into the region in the 1830s. They altered waterways, cleared trees and forests, drained swamps, dug up prairie, made plowable farmland, laid railroad lines, and created plats for sale and development. It does not sound like this mound was in the way of anything; rather, it offered raw material for objects helpful to new development.
I am grateful for maps and other efforts that show what metropolitan regions looked like before white European settlers and then prior to all of the urbanization and suburbanization of the 1800s onward. For example, I have seen multiple versions of this for Manhattan and New York City, discussing and showing streams, hills, and habitats that are hard to imagine in such a large city. Likewise, maps and narratives of the Chicago region highlight a verdant area at the southwest edge of Lake Michigan – that just happened to be an easy portage point to connect the Great Lakes and the Mississippi. Today, it is hard to imagine significant hills or mounds in a region where the flat grid predominates.