Chicago O'Hare International Airport (ORD) has uncovered a 50-ton boulder buried approximately 30 feet (9 meters) beneath its airfield, turning an unexpected construction discovery into a public naming contest, according to CBS News Chicago. The rock was found during excavation work for a stormwater management facility connected to the airport’s ambitious ORDNext expansion project. After receiving nearly 3,000 public suggestions, the City of Chicago announced six finalists on October 16, 2026, and opened online voting to decide the boulder’s official name. The winning entry will eventually be displayed alongside the enormous rock in a new airport exhibit.
Although the discovery has little direct connection to aircraft operations, it offers an unusual glimpse into the work taking place beneath one of the world's busiest airports. O’Hare is undergoing a major redevelopment to modernize its infrastructure and expand its terminal facilities, which requires extensive excavation and construction. The boulder was not an anticipated attraction, but its size and unusual discovery have given the project a distinctly Chicago twist. Instead of removing it from the construction site, airport officials decided to invite the public to help give the geological curiosity a permanent identity.
Six Names Compete For O’Hare’s Biggest Rock
Chicago O'Hare International Airport, Simple Flying
Chicago's Department of Aviation discovered the boulder while workers excavated the South Detention Basin, a stormwater management facility being developed as part of the ORDNext terminal expansion program. According to CBS Chicago, the rock measures approximately 11.5 feet (3.5 meters) wide, 8 feet (2.4 meters) deep, and 7.5 feet (2.3 meters) tall. Its estimated weight of 50 tons makes it a substantial obstacle during excavation, although available reports do not indicate it disrupted flight operations. The discovery was made beneath the airfield surface.
The public naming campaign began in September, inviting people to submit their ideas through an online form. Following nearly 3,000 submissions, officials selected six finalists for a public vote, which remains open until 5 p.m. Central Daylight Time on November 2, 2026.
The shortlisted names are:
- Sweet Stone Chicago
- No ORDinary Rock
- Chicago Rocks
- O'Rock
- Orchard Rock
- Da Rock
The public can vote in the city's announced online contest, and the winning name will appear in an airport exhibit.
The contest also builds on the airport's efforts to engage travelers and the wider Chicago community during its ongoing transformation. What began as an ordinary excavation task has become an opportunity to create a small, memorable attraction connected to the redevelopment. According to the initial contest announcement, the winning name will not be carved into the boulder itself; instead, it will accompany it in its planned airport display.
What Lies Beneath Chicago’s Busiest Airport?
The boulder is made of dolostone, a sedimentary carbonate rock composed primarily of the mineral dolomite, or calcium magnesium carbonate. Geologists identified the material as limestone-related, which can form when magnesium-rich groundwater alters existing limestone deposits. Its presence beneath O’Hare highlights the geological conditions construction teams may encounter during major infrastructure projects. Although the discovery is unusual in its scale, the rock formed naturally over millions of years.
The excavation is part of a much larger effort to improve O’Hare's facilities and accommodate its future needs. ORDNext encompasses the airport's major terminal expansion, which Chicago has described as the largest terminal expansion in its history. The project includes extensive construction and infrastructure work, so excavation extends well beyond the passenger-facing areas where travelers normally see airport development. Stormwater management is particularly important at a large airport, where drainage infrastructure must support extensive paved surfaces and help manage rainfall around runways, taxiways, and other facilities.
The boulder also demonstrates how construction discoveries can become unexpected public-relations opportunities. Airport officials initially referred to it internally as the "O'Hare bean," a playful reference to Chicago's famous Cloud Gate sculpture, commonly known as The Bean. The naming contest takes that informal nickname a step further by letting residents and travelers help shape the airport's history.
O’Hare’s Expansion Continues
O’Hare is a major hub for both 
United Airlines and 
American Airlines and a key gateway for domestic and international travelers. Improvements to its terminals and supporting infrastructure matter not only for Chicago but also for airlines and passengers who depend on the airport for connections. The discovery of the mega stone has attracted attention to the less visible engineering work supporting the expansion. The planned exhibit will give visitors a tangible reminder of what construction crews found while preparing the airport for its next phase.
For now, the public decides. The winning name is expected to appear alongside the boulder in a new airport exhibit. Whether Chicago ultimately chooses the playful O'Rock, the aviation-themed No ORDinary Rock, or one of the other finalists, the 50-ton discovery has already secured a place in O’Hare's expansion story.