Kevin Tu

Thornton Quarry, June 2020

I-294 runs through the middle of the quarry. What a view!

The faint Chicago skyline

Part of the quarry, converted to a reservoir, supplies 8 billion gal of storm-water storage for the metro area

Mining contamination colors the retention water a stunning turquoise

A BNSF rail line also runs through the quarry

The metro area has expanded to surround the quarry since it opened in 1928

Thornton Quarry is one of the largest aggregate quarries in the world

Bird's eye view

At present, the quarry is 1.5 miles long, 0.5 miles wide, and up to 450 feet deep

Bird's eye view of this stretch of I-294

A sheer rock wall

Mining ever deeper. Note this old access tunnels now suspended midair

The surrounding area is deceptively green from this perspective

The ctf_2fort complex irl

High albedo surface - makes setting exposure difficult

Panorama of the main quarry