Women Road Builders members had an up-close look at two important parts of the road construction process during an Oct. 6, 2026, tour of Gallagher Asphalt and the Thornton Quarry in Thornton, Ill.
The event brought together women from across the transportation and construction industries to learn more about the materials and operations behind the roads they help plan, build and maintain.
Hosted at Gallagher Asphalt's Thornton headquarters, the afternoon event included a tour of the asphalt plant and a visit to the nearby Heidelberg Thornton Quarry. According to Women Road Builders, the program was designed to give participants a better understanding of how asphalt is produced and where the materials used in road construction originate.
For Construction Equipment Guide, the visit provided an opportunity to see the operations behind these essential construction materials and hear from the family-owned company as it approaches its 100th anniversary.
“We're very excited and happy to have everyone here,” said Will Gallagher, president of Gallagher Asphalt, told Construction Equipment Guide. “It's a very tight-knit, very smart, hard-working group within the industry, and we need different ways of thinking to move forward as an industry. With that, we're very happy to help and support and host Women Road Builders today.”
Four Generations of Asphalt Production
Founded in 1928 by James F. Gallagher, Gallagher Asphalt has grown into a fourth-generation, family-owned asphalt manufacturer and general contractor serving the Chicagoland area.
According to the company's website, Gallagher Asphalt provides hot-mix asphalt manufacturing, paving, milling, aggregate base and excavation, site concrete, quality control and other pavement-related services. Its operations support projects ranging from neighborhood streets to major infrastructure and commercial developments.
The company operates three asphalt plant locations in Thornton, Joliet and Bourbonnais, Ill., allowing it to serve customers throughout the region.
Gallagher said the company's history began with his great-grandfather, who left school in the seventh grade to help support his mother and seven siblings.
“He was really an innovator and pioneer within the industry,” Gallagher said of his great-grandfather. “He helped build the company into what it is today and build the interstate system throughout Chicagoland.”
With the company now approaching its centennial, Gallagher said the family looks forward to continuing that legacy.
“We're excited to see it go another 100 years here shortly,” he said.
That history reflects the important role regional asphalt producers have played in developing and maintaining the transportation network. Asphalt manufacturing and paving operations connect the supply of construction materials with the contractors and agencies responsible for delivering roadway projects.
Gallagher Asphalt also emphasizes efficiency and recycling in its operations. According to the company, its Thornton and Bourbonnais plants rank in the top 25 percent nationwide for energy efficiency and are the only ENERGY STAR-certified asphalt plants in Illinois.
The company also identifies asphalt recycling as an important part of its approach to conserving resources and reducing costs.
Thornton Quarry Supplies Essential Materials
The quarry portion of the tour highlighted another essential component of roadway construction: aggregates.
The Thornton Quarry, a major limestone-producing operation in Thornton, Ill., is among the largest commercial stone quarries in the world. According to the Thornton Historical Society's website, the quarry measures approximately 1.5 mi. long, half a mile wide and 450 ft. deep at its deepest point.
The quarry's history stretches back nearly two centuries. The first settlers arrived in Thornton in 1834, and Gurdon Hubbard opened an early quarry on Kinzie Street in 1836. That operation was abandoned because the stone was too deep and of poor quality. Additional quarry operations followed in the 1840s and 1850s.
The quarry expanded significantly during the early 20th century. The quarry north of Ridge Road opened in 1924, and a tunnel connecting the northern and southern sections was developed in 1926. Material Service Corporation purchased the property in 1938.
Today, the quarry is owned by Hanson Material Service and produces aggregates, stone, sand, metallurgical stone, mineral filler and other products. The Thornton Historical Society reports that the operation produces more than 7 million tons of rock products annually.
Those materials serve a variety of construction applications. Crushed stone and other aggregates are used in concrete, asphalt mixtures and road base, making quarry operations an important part of the infrastructure supply chain.
The site also has a geological history that predates modern construction by hundreds of millions of years. According to the Thornton Historical Society, the limestone contains fossils from an ancient marine environment that existed during the Silurian Period, when much of the region was covered by a shallow tropical sea.
The fossils provide evidence of coral reefs and marine life that once occupied the area, illustrating how geological processes formed the limestone now extracted for commercial use.
For road builders, the quarry's significance is practical as well as historical: it supplies the mineral materials that help form the foundation and surface of transportation infrastructure.
Building Connections Across Industry
Beyond the technical aspects of asphalt manufacturing and aggregate production, the event supported Women Road Builders' broader mission of professional development and relationship building.
According to the organization, Women Road Builders is a nonprofit dedicated to improving the road construction industry through education, professional development and connections among women working in the field. Its mission is to support the advancement and success of professional women in an industry traditionally dominated by men, while welcoming others who share its goals.
The Gallagher Asphalt tour offered participants from engineering, construction, communications, planning and related fields an opportunity to learn about operations outside their own specialties.
Understanding how construction materials are produced and supplied can help industry professionals see the broader processes involved in delivering infrastructure projects. It also creates opportunities for participants to exchange knowledge, develop professional relationships and gain a deeper appreciation for the work performed throughout the industry.
Gallagher welcomed the opportunity to support that effort, noting the value of different perspectives in moving the industry forward.
With Gallagher Asphalt approaching a century in business and the Thornton Quarry continuing to supply materials for construction, the tour connected the region's long industrial history with the people and operations that will help shape its future infrastructure.
For more information, visit womenroadbuilders.com, gallagherasphalt.com and thorntonilhistory.com/thornton-quarry.
