Massive Boulder Unearthed at O’Hare International Airport: A Rock Enthusiast’s Delight

Ron Pitelka began his fascination with rocks at the age of 23 when he first took a boulder from a construction site in Chicago’s southwest suburbs. His collection has significantly grown since then, comprising several hundred rocks, with some displayed around his residence. However, none of these rocks compare to the colossal boulder discovered at O’Hare International Airport this summer.

During a project for O’Hare’s terminal modernization, Pitelka and bulldozer operator Matt Tracy unearthed a 50-ton boulder. The Chicago Department of Aviation discovered the rock while excavating a stormwater detention basin. Found 30 feet underground, the boulder drew attention to its size.

Ron Pitelka in his excavator with the 50-ton O’Hare boulder on the day it was dug up at the airport, photographed by bulldozer operator Matt Tracy.

A geologist identified the boulder as dolostone, a carbonate rock related to limestone, which forms much of Illinois’s bedrock. Dolostone became the state’s official rock after a campaign by local school children. The Aviation Department started a contest to name the boulder, receiving over 2,300 suggestions including unique names like ‘Da Layover’ and ‘The BaRock Obama Presidential Memorial Airport Boulder.’ Finalists will be chosen by Aviation staff, with the public voting on the winner.

Pitelka was thrilled with the naming contest news. He often felt disheartened when asked to bury or break beautiful boulders on job sites. The historical significance of the boulder makes this find particularly special; it formed over 400 million years ago when the Chicago region was a tropical sea.

Pat McLaughlin, a principal research scientist, explained the rock’s history: “The critters in the shallow sea contributed to the formation of limestone, later turning into dolostone.”

Now, the boulder is on public display at the O’Hare Multi-Modal Facility, already attracting interest for its notable size. For Pitelka, whose interest in excavation started as a child on his family’s construction projects, the discovery is exhilarating.

Looking to the future, he imagines others discovering the boulder long after he is gone. While many dream of finding fossils or other treasures, Pitelka finds equal joy and fulfillment in unearthing such significant geological features. He hopes the boulder’s name will reflect its geological roots, suggesting the simple name ‘Geo.’