Thornton Quarry

The quarry spans 1.5 miles in length, 0.5 miles in width, and reaches depths of 450 feet, producing seven million tons of rock annually.

Operations began in 1836 when Gurdon Hubbard established the first quarry on Kinzie Street, though it was later abandoned due to low-quality stone deposits.

The site functions as an educational center where students and professionals study geological formations and examine marine fossils from ancient coral reefs.

Interstate 80 and 294 cross the quarry via a dryland dike, while the facility serves as a reservoir in the Chicago Deep Tunnel project.

A meteorite discovered in 1994 at the quarry dates back 4.6 billion years, indicating it struck Earth when the area was an underwater coral reef.

Location: Illinois

GPS coordinates: 41.57100,-87.62200

Latest update: May 27, 2025 08:24