The company started in 1973, with a 22-year-old Bill Karson delivering stone and gravel for local quarries. In the next few years, he expanded and bought his first sandpit and limestone quarry. Throughout the 1980s, Karson continued to build the company, growing its aggregate business and adding excavation and road construction services. With the purchase of a batch plant and asphalt pavers and rollers in 1997, Karson became a fully integrated road builder from quarry to finished road. The Karson Group now specializes in road construction, paving, site development, utilities, aggregate production and equipment rental. It was purchased by Aecon Group in 2007.