 Gallagher Asphalt Corporation has been operating on the grounds of the quarry since 1928.A dryland dike carries Interstate 80/Interstate 294/Tri-State Tollway over the quarry.As part of the Chicago Deep Tunnel project, both Thornton Quarry and McCook Quarry will serve as reservoirs to reduce the backflow of stormwater and sewage from Chicago area rivers into Lake Michigan.