The canyon is a deep gorge carved by the Apple River when its course was diverted during the Illinoian Stage, 132,000–300,000 years ago.

The mill pond waters tore down Clear Creek and poured into the South Fork Apple River, rushing toward Millville.

A Mr. Dean owned a blacksmith shop, a John W. Marshall started a dry goods store, another resident, Eldridge Howard built a large house and opened a tavern within it.

[2] 1840 census figures show a population of 62, though local historians have given estimates for the late 1830s at 330, a number that likely included surrounding rural farms.

[2] Of the 1850 population of Millville, 19 people were engaged in commercial or trade occupation, 17 were farmers or laborers and at least 6 were involved in lead mining.

One such survey occurred when the Illinois Department of Transportation (IDOT) prepared to replace an old bridge across the South Fork Apple River within the state park.

An archaeological team, from the Resource Investigation Program at the University of Illinois, reported a buried layer of top soil about 70–80 cm beneath the surface with extensive 19th century ceramics and mortar as well as an area of stone that may have been part of a building foundation.

[2] The team determined that the building of the bridge would disturb the site and recommended further survey, no other work was done at the right-of-way, and IDOT approved the project in December 1991.

Artifact recovery at the site in the future has the potential to yield new information about the day-to-day habits of those living in Millville.